[WX-1317] Remove Akka 'server' header from all HTTP responses (#7379)

server/src/main/resources/application.conf

@@ -8,8 +8,12 @@ akka {
     server {
       request-timeout = 40s
       bind-timeout = 5s
+      # By default, akka includes an HTTP header in responses that looks like:
+      # server=akka-http/10.20.1
+      # For better app sec, we suppress this to make it harder for attackers to learn about our system.
+      # Akka doc: https://doc.akka.io/docs/akka-http/current/configuration.html
+      server-header = ""
     }
-
     client.connecting-timeout = 40s
 
     # Inspired by https://broadworkbench.atlassian.net/browse/CROM-6738