Revert f6ae101 (#266)

Author: emerkle826

management-api-server/src/test/java/com/datastax/mgmtapi/NonDestructiveOpsIT.java

@@ -931,7 +931,7 @@ private String responseAsString(FullHttpResponse r) {
     return null;
   }
 
-  private synchronized Pair<Integer, String> responseAsCodeAndBody(FullHttpResponse r) {
+  private Pair<Integer, String> responseAsCodeAndBody(FullHttpResponse r) {
     return Pair.of(r.status().code(), r.content().toString(UTF_8));
   }
 }