Fix flaky test in BasicCassandraPersistentTupleEntityUnitTests.

Closes #618

Author: mp911de

spring-data-cassandra/src/test/java/org/springframework/data/cassandra/core/mapping/BasicCassandraPersistentTupleEntityUnitTests.java

@@ -135,6 +135,5 @@ private static class NoElements {
 	private static class MissingAnnotation {
 
 		String street;
-		String city;
 	}
 }