update german translation

includes/controller/event_config_controller.php

@@ -73,11 +73,6 @@ function event_config_edit_controller() {
       error(_("The event end date has to be before the teardown end date."));
     }
     
-    if ($event_start_date != null && $event_end_date != null && $event_start_date > $event_end_date) {
-      $ok = false;
-      error(_("The event start date has to be before the event end date."));
-    }
-    
     if ($buildup_start_date != null && $teardown_end_date != null && $buildup_start_date > $teardown_end_date) {
       $ok = false;
       error(_("The buildup start date has to be before the teardown end date."));

includes/view/EventConfig_view.php

@@ -20,11 +20,11 @@ function EventConfig_edit_view($event_name, $event_welcome_msg, $buildup_start_d
                   form_textarea('event_welcome_msg', _("Event Welcome Message"), $event_welcome_msg),
                   form_info('', _("Welcome message is shown after successful registration. You can use markdown.")) 
               ]),
-              div('col-md-3', [
+              div('col-md-3 col-xs-6', [
                   form_date('buildup_start_date', _("Buildup date"), $buildup_start_date),
                   form_date('event_start_date', _("Event start date"), $event_start_date) 
               ]),
-              div('col-md-3', [
+              div('col-md-3 col-xs-6', [
                   form_date('teardown_end_date', _("Teardown end date"), $teardown_end_date),
                   form_date('event_end_date', _("Event end date"), $event_end_date) 
               ])