Provide Module Identifier via MongoRepositoryConfigurationExtension

Closes: #4092

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/config/MongoRepositoryConfigurationExtension.java

@@ -56,6 +56,11 @@ public class MongoRepositoryConfigurationExtension extends RepositoryConfigurati
 		return MongoRepositoryFactoryBean.class.getName();
 	}
 
+	@Override
+	public String getModuleIdentifier() {
+		return getModulePrefix();
+	}
+
 	@Override
 	protected Collection<Class<? extends Annotation>> getIdentifyingAnnotations() {
 		return Collections.singleton(Document.class);