fix(upload): make sure variable is always defined

Previously variable $QUM might not be defined.
This would have happened, if the permission check threw a QUI\Exception

lib/QUI/Upload/bin/upload.php

@@ -13,30 +13,34 @@
 
 try {
     QUI\Permissions\Permission::checkPermission('quiqqer.frontend.upload');
+} catch (\Exception $Exception) {
+    QUI\System\Log::writeDebugException($Exception);
+}
 
-    $QUM = new QUI\Upload\Manager();
-    QUI::getAjax();
+$QUM = new QUI\Upload\Manager();
+QUI::getAjax();
 
+try {
     $uploadResult = $QUM->init();
-
-    if (!empty($uploadResult)) {
-        $result = [
-            'result' => $uploadResult,
-            'maintenance' => QUI::conf('globals', 'maintenance') ? 1 : 0
-        ];
-
-        if (QUI::getMessagesHandler()) {
-            $result['message_handler'] = QUI::getMessagesHandler()->getMessagesAsArray(
-                QUI::getUserBySession()
-            );
-        }
-
-        // maintenance flag
-        echo '<quiqqer>' . json_encode($result) . '</quiqqer>';
-    }
-} catch (QUI\Exception $Exception) {
+} catch (\QUI\Exception $Exception) {
     QUI\System\Log::writeDebugException($Exception);
     $QUM->flushException($Exception);
-} catch (\Exception $Exception) {
-    QUI\System\Log::writeDebugException($Exception);
 }
+
+if (empty($uploadResult)) {
+    exit;
+}
+
+$result = [
+    'result' => $uploadResult,
+    'maintenance' => QUI::conf('globals', 'maintenance') ? 1 : 0
+];
+
+if (QUI::getMessagesHandler()) {
+    $result['message_handler'] = QUI::getMessagesHandler()->getMessagesAsArray(
+        QUI::getUserBySession()
+    );
+}
+
+// maintenance flag
+echo '<quiqqer>' . json_encode($result) . '</quiqqer>';