637: Default generator should not be static

Change-Id: I3bb119f3f7debeb0d45ff81dc9154e26635f03bb
(cherry picked from commit 102cbbd)

Author: janssk1

src/main/java/com/rabbitmq/client/RpcClient.java

@@ -80,8 +80,6 @@ public class RpcClient {
         }
     };
 
-    public static Supplier<String> DEFAULT_CORRELATION_ID_GENERATOR = new IncrementingCorrelationIdGenerator("");
-
     private final Function<Object, Response> _replyHandler;
 
     /** Map from request correlation ID to continuation BlockingCell */

src/main/java/com/rabbitmq/client/RpcClientParams.java

@@ -55,7 +55,7 @@ public class RpcClientParams {
      */
     private Function<Object, RpcClient.Response> replyHandler = RpcClient.DEFAULT_REPLY_HANDLER;
 
-    private Supplier<String> correlationIdGenerator = RpcClient.DEFAULT_CORRELATION_ID_GENERATOR;
+    private Supplier<String> correlationIdGenerator = new IncrementingCorrelationIdGenerator("");
 
     /**
      * Set the channel to use for communication.