static path for wagtail.contrib.settings should be 'wagtailsettings' to avoid name clashes

gulpfile.js/config.js

@@ -54,7 +54,9 @@ var apps = [
             'wagtailstyleguide/scss/styleguide.scss'
         ],
     }),
-    new App('wagtail/contrib/settings'),
+    new App('wagtail/contrib/settings', {
+        'appName': 'wagtailsettings',
+    }),
 ];
 
 module.exports = {

wagtail/contrib/settings/forms.py

@@ -11,7 +11,7 @@ class SiteSwitchForm(forms.Form):
 
     class Media:
         js = [
-            'settings/js/site-switcher.js',
+            'wagtailsettings/js/site-switcher.js',
         ]
 
     def __init__(self, current_site, model, **kwargs):