Fixed unstable tests: ObjectManager Attribute creation/migration fails on fast/slow systems.

test/browser_test_helper.rb

@@ -4243,7 +4243,7 @@ wait untill text in selector disabppears
       browser: instance,
     )
     title_text = instance.find_elements(css: '.modal .modal-title').first.text
-    if title_text == 'Zammad is restarting...'
+    if ['Zammad is restarting...', 'Zammad need a restart!'].include?(title_text)
       # in the complex case, wait for server to restart
       modal_disappear(
         browser: instance,
@@ -4617,6 +4617,8 @@ wait untill text in selector disabppears
       return
     end
 
+    modal_disappear(browser: instance)
+
     11.times do
       element = instance.find_elements(css: 'body')[0]
       text = element.text