Fix startup error loading Zotero service

https://forums.zotero.org/discussion/63869/5-0-beta-standalone-blank-ui-upon-restart
https://forums.zotero.org/discussion/63865/5-0-beta-library-wont-load

Adding include.js to hiddenWindow.xul in 66549f9e6d seems to have
created a race condition in which the Zotero service would fail on the
third startup after the JS cache was cleared (e.g., on a new version,
-purgecaches, or other changes in the profile). So, don't do that.

Hopefully this isn't caused by other uses (e.g., in plugins) of
include.js and was only happening because the hidden window is launched
concurrently with standalone.xul on macOS.

chrome/content/zotero-platform/mac/standalone/menuOverlay.xul

@@ -83,7 +83,7 @@
         <menuitem id="menu_preferences"
 				label="&preferencesCmdMac.label;"
 				key="key_preferencesCmdMac"
-				oncommand="Zotero.Utilities.Internal.openPreferences();"/>
+				oncommand="Components.classes['@mozilla.org/appshell/window-mediator;1'].getService(Components.interfaces.nsIWindowMediator).getMostRecentWindow('navigator:browser').Zotero.Utilities.Internal.openPreferences();"/>
         <menuitem id="menu_mac_services"
 				label="&servicesMenuMac.label;"/>
         <menuitem id="menu_mac_hide_app"

chrome/content/zotero/standalone/hiddenWindow.xul

@@ -38,7 +38,6 @@
 
 <window id="main-window" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
     <script type="application/javascript" src="chrome://global/content/globalOverlay.js"/>
-    <script type="application/javascript" src="chrome://zotero/content/include.js"/>
 	<commandset id="mainCommandSet">
 		<!--FILE-->
 		<command id="cmd_quitApplication" oncommand="goQuitApplication();"/>