Always send a progress message at the end of a sync #5290

Some listeners detect whether a sync is finished by checking
for isUpdatingEstimates and completedFiles >= totalFiles. But
if a sync didn't transfer any files we never sent signal
with these values. Now we do.

src/libsync/syncengine.cpp

@@ -1070,6 +1070,11 @@ void SyncEngine::slotFinished(bool success)
     }
 
     _journal->commit("All Finished.", false);
+
+    // Send final progress information even if no
+    // files needed propagation
+    emit transmissionProgress(*_progressInfo);
+
     emit treeWalkResult(_syncedItems);
     finalize(success);
 }