open course-wizard in dialog, closes #1455

Closes #1455

Merge request studip/studip!905

app/controllers/my_courses.php

@@ -883,7 +883,7 @@ class MyCoursesController extends AuthenticatedController
                 _('Neue Veranstaltung anlegen'),
                 URLHelper::getURL('dispatch.php/course/wizard'),
                 Icon::create('seminar+add')
-            );
+            )->asDialog();
         }
 
         $setting_widget->addLink(
@@ -896,7 +896,7 @@ class MyCoursesController extends AuthenticatedController
                 _('Neue Studiengruppe anlegen'),
                 URLHelper::getURL('dispatch.php/course/wizard', ['studygroup' => 1]),
                 Icon::create('studygroup+add')
-            )->asDialog('size=auto');
+            )->asDialog();
         }
 
         $this->setGroupingSelector($group_field);