Use use module identifier to obtain module prefix in KeyValueRepositoryConfigurationExtension.

Closes #542

src/main/java/org/springframework/data/keyvalue/repository/config/KeyValueRepositoryConfigurationExtension.java

@@ -62,7 +62,7 @@ public abstract class KeyValueRepositoryConfigurationExtension extends Repositor
 
 	@Override
 	protected String getModulePrefix() {
-		return "keyvalue";
+		return getModuleIdentifier();
 	}
 
 	@Override