Send sync message when unpinning.

app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java

@@ -230,6 +230,7 @@ public class ApplicationContext extends Application implements AppForegroundObse
               .addPostRender(() -> ActiveCallManager.clearNotifications(this))
               .addPostRender(RestoreOptimizedMediaJob::enqueueIfNecessary)
               .addPostRender(RetryPendingSendsJob::enqueueForAll)
+              .addPostRender(() -> AppDependencies.getPinnedMessageManager().scheduleIfNecessary())
               .execute();
 
     Log.d(TAG, "onCreate() took " + (System.currentTimeMillis() - startTime) + " ms");