fix crashes when deleting stamps or getting an error when saving

src/save/ServerSaveActivity.cpp

@@ -174,8 +174,8 @@ void ServerSaveActivity::Save()
 		virtual void ConfirmCallback(ConfirmPrompt::DialogueResult result) {
 			if (result == ConfirmPrompt::ResultOkay)
 			{
-				a->saveUpload();
 				a->Exit();
+				a->saveUpload();
 			}
 		}
 		virtual ~PublishConfirmation() { }
@@ -189,8 +189,8 @@ void ServerSaveActivity::Save()
 		}
 		else
 		{
-			saveUpload();
 			Exit();
+			saveUpload();
 		}
 	}
 	else

src/tasks/TaskWindow.cpp

@@ -60,7 +60,7 @@ void TaskWindow::Exit()
 	if(ui::Engine::Ref().GetWindow()==this)
 	{
 		ui::Engine::Ref().CloseWindow();
-		delete this;
+		SelfDestruct();
 	}
 }