prepare release 1.15 (#2707)

* bump version
* fix invisible class on labels
* fail safe removal of foreign key
* check if optional form field exists before accessing it
* silently ignore stopped timesheets
* prevent colliding parameter names
* make sure decimal duration is always rendered with two decimals
* simplify translation
* fix #2751 ANSI_QUOTES
* rename composer task
* fix billable statistic rates
* added missing translation for export

src/Controller/UserController.php

@@ -126,7 +126,7 @@ final class UserController extends AbstractController
 
             $this->flashSuccess('action.update.success');
 
-            if ($editForm->get('create_more')->getData() !== true) {
+            if ($editForm->has('create_more') && $editForm->get('create_more')->getData() !== true) {
                 return $this->redirectToRoute('user_profile_edit', ['username' => $user->getUsername()]);
             }