Fix various sporadic test failures

* Increase a `default-delay="1000"` for `GatewayInterfaceTests`
to test the late reply scenario
* Use a `ConcurrentHashMap` for `JdbcMessageStore.queryCache`
to avoid a possible `ConcurrentModificationException`

spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayInterfaceTests-context.xml

@@ -25,7 +25,7 @@
 		<int:header-enricher>
 			<int:error-channel ref="errorChannel" overwrite="true"/>
 		</int:header-enricher>
-		<int:delayer id="delayer" default-delay="100"/>
+		<int:delayer id="delayer" default-delay="1000"/>
 	</int:chain>
 
 

spring-integration-jdbc/src/main/java/org/springframework/integration/jdbc/store/JdbcMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,11 +22,11 @@
 import java.sql.Timestamp;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Stream;
 
 import javax.sql.DataSource;
@@ -171,7 +171,7 @@ public String getSql() {
 
 	private final String vendorName;
 
-	private final Map<Query, String> queryCache = new HashMap<>();
+	private final Map<Query, String> queryCache = new ConcurrentHashMap<>();
 
 	private String region = "DEFAULT";