Upgrade log4j 2.15.0 => 2.17.0

This change upgrades log4j to patch fixes for recently documented
CVE-2021-45046 CVE-2021-45105 vulnerabilities related to the Log4Shell
exploit.

Like the earlier fix, Bisq does not appear to be vulnerable to these
exploits because it does not use log4j directly, only transitively
depends on it. Nevertheless, the upgrade is still the safe bet.

build.gradle

@@ -584,7 +584,7 @@ configure(project(':pricenode')) {
         "Implementation-Title": project.name,
         "Implementation-Version": version)
 
-    ext['log4j2.version'] = '2.15.0'
+    ext['log4j2.version'] = '2.17.0'
 
     dependencies {
         implementation project(":common")

gradle/verification-metadata.xml

@@ -1888,6 +1888,11 @@
             <sha256 value="3f745daa4ea6dc2606525bd4279bf30062066bd223866adb7f5eee46dcf76a03" origin="Generated by Gradle"/>
          </artifact>
       </component>
+      <component group="org.apache.logging.log4j" name="log4j" version="2.17.0">
+         <artifact name="log4j-2.17.0.pom">
+            <sha256 value="8704606faeb779d6d2904f02ca616e0b981fe389d9fe9b89ec84a1e42aee81d2" origin="Generated by Gradle"/>
+         </artifact>
+      </component>
       <component group="org.apache.logging.log4j" name="log4j-api" version="2.11.0">
          <artifact name="log4j-api-2.11.0.jar">
             <sha256 value="fa5828950269b0ae425c96d889f18f40b336e9fa886841ae06bb9225511f1217" origin="Generated by Gradle"/>
@@ -1912,6 +1917,14 @@
             <sha256 value="cc75a1281e48700547a81336b564f512a7226e995800bf88ab849ab5adbffa47" origin="Generated by Gradle"/>
          </artifact>
       </component>
+      <component group="org.apache.logging.log4j" name="log4j-api" version="2.17.0">
+         <artifact name="log4j-api-2.17.0.jar">
+            <sha256 value="ab9cadc80e234580e3f3c8c18644314fccd4b3cd3f7085d4e934866cb561b95d" origin="Generated by Gradle"/>
+         </artifact>
+         <artifact name="log4j-api-2.17.0.pom">
+            <sha256 value="6422d9af59acb0077e8a91c7c34a4062ff56a9731c34836a72427084e27aa479" origin="Generated by Gradle"/>
+         </artifact>
+      </component>
       <component group="org.apache.logging.log4j" name="log4j-bom" version="2.14.1">
          <artifact name="log4j-bom-2.14.1.pom">
             <sha256 value="a9cef896837f42c6d950b1ce44e2bc1eeeadb246d6c484e07ddd99fb8c022c59" origin="Generated by Gradle"/>
@@ -1922,6 +1935,11 @@
             <sha256 value="99b95442cfaf64ba478ef06d869fefdf3dd959fec78263e59f55cec5ac98b485" origin="Generated by Gradle"/>
          </artifact>
       </component>
+      <component group="org.apache.logging.log4j" name="log4j-bom" version="2.17.0">
+         <artifact name="log4j-bom-2.17.0.pom">
+            <sha256 value="befed280f53ce4866012c9d82b1a7ab46efe26ea3969aee9172845e3a114f222" origin="Generated by Gradle"/>
+         </artifact>
+      </component>
       <component group="org.apache.logging.log4j" name="log4j-core" version="2.11.0">
          <artifact name="log4j-core-2.11.0.jar">
             <sha256 value="c32029b32da3d8cf2feca0790a4bc2331ea7eb62ab368a8980b90c7d8c8101e0" origin="Generated by Gradle"/>
@@ -1946,6 +1964,14 @@
             <sha256 value="79c17ecc56a70d466c13bd5926c75c42d7f8bcdbbcfb7d9770e616c013531d1a" origin="Generated by Gradle"/>
          </artifact>
       </component>
+      <component group="org.apache.logging.log4j" name="log4j-to-slf4j" version="2.17.0">
+         <artifact name="log4j-to-slf4j-2.17.0.jar">
+            <sha256 value="df8a9a9d06368a87abd04051597310cc7a501762ab0cd7492ba106df92862c78" origin="Generated by Gradle"/>
+         </artifact>
+         <artifact name="log4j-to-slf4j-2.17.0.pom">
+            <sha256 value="24d195ba852929def67345ea9c2a52e6d6d470b86bee3a2fd64e087fe5a0151b" origin="Generated by Gradle"/>
+         </artifact>
+      </component>
       <component group="org.apache.tomcat.embed" name="tomcat-embed-core" version="9.0.54">
          <artifact name="tomcat-embed-core-9.0.54.jar">
             <sha256 value="287f5b91c434df0eef104389c52c480ab4b66f80b494c16607fd82ae9217f8e3" origin="Generated by Gradle"/>