fix indentation and note that stop should be idempotent

Author: jsonbailey

lib/ldclient-rb/impl/data_system/fdv2.rb

@@ -343,8 +343,8 @@ def synchronizer_loop
             # Ensure we always set the ready event when exiting
             @ready_event.set
             @lock.synchronize do
-@active_synchronizer&.stop
-@active_synchronizer = nil
+              @active_synchronizer&.stop
+              @active_synchronizer = nil
             end
           end
         end

lib/ldclient-rb/interfaces/feature_store.rb

@@ -103,6 +103,9 @@ def initialized?
       #
       # Performs any necessary cleanup to shut down the store when the client is being shut down.
       #
+      # This method should be idempotent - it is safe to call it multiple times, and subsequent
+      # calls after the first should have no effect.
+      #
       # @return [void]
       #
       def stop