b=475147, Changes to custom pref pane support (should have been in the main patch)

runtime/chrome/content/preferences/connection.xul

@@ -79,7 +79,7 @@
       <preference id="network.proxy.backup.gopher_port"  name="network.proxy.backup.gopher_port"  type="int"/>
     </preferences>
     
-    <script type="application/x-javascript" src="chrome://webrunner/content/connection.js"/>
+    <script type="application/x-javascript" src="chrome://webrunner/content/preferences/connection.js"/>
 
     <stringbundle id="preferencesBundle" src="chrome://webrunner/locale/preferences/preferences.properties"/>