Improve exception message with jar mismatch

(currently commented in this version).

Author: garyrussell

spring-kafka-test/src/main/java/org/springframework/kafka/test/rule/KafkaEmbedded.java

@@ -103,7 +103,9 @@ public class KafkaEmbedded extends ExternalResource implements KafkaRule, Initia
 //						int.class, scala.Option.class, int.class, boolean.class);
 //			}
 //			catch (NoSuchMethodException | SecurityException e) {
-//				throw new RuntimeException("Failed to determine TestUtils.createBrokerConfig() method");
+//				throw new RuntimeException("Failed to determine TestUtils.createBrokerConfig() method, "
+//						+ "possible mismatched versions of the client/broker jars; see the appendix in "
+//						+ "the reference manual when overriding kafka-clients to version " + clientVersion);
 //			}
 //		}
 //		else {