Fix replace_address after CASSANDRA-7356 broke it

Patch by Tyler Hobbs and Marcus Eriksson; reviewed by Brandon Williams for CASSANDRA-7356
Merge branch 'cassandra-1.2' into cassandra-2.0

Conflicts:
	src/java/org/apache/cassandra/config/DatabaseDescriptor.java
	src/java/org/apache/cassandra/service/StorageService.java