Fix app.update.auto on Windows

On Windows, `app.update.auto` is now a per-installation pref stored in
C:\ProgramData\Zotero\Updates\[id]\update-config.json so that it can be
used by the background update service. We don't have a background update
service, so we force it to continue using the profile pref.

app/assets/prefs.js

@@ -97,6 +97,8 @@ pref("extensions.update.url", "");
 // Don't try to load the "Get Add-ons" tab on first load of Add-ons window
 pref("extensions.ui.lastCategory", "addons://list/extension");
 
+// Not set on Windows in Firefox anymore since it's a per-installation pref,
+// but we override that in fetch_xulrunner
 pref("app.update.auto", true);
 
 // URL user can browse to manually if for some reason all update installation

app/scripts/fetch_xulrunner

@@ -129,6 +129,8 @@ function modify_omni {
 	
 	# Don't use Mozilla Maintenance Service on Windows
 	replace_line 'MOZ_MAINTENANCE_SERVICE:' 'MOZ_MAINTENANCE_SERVICE: false \&\&' modules/AppConstants.jsm
+	# Continue using app.update.auto in prefs.js on Windows
+	replace_line 'PER_INSTALLATION_PREFS_PLATFORMS = \["win"\]' 'PER_INSTALLATION_PREFS_PLATFORMS = []' modules/UpdateUtils.jsm
 	
 	# Prompt if major update is available instead of installing automatically on restart
 	replace_line 'if \(!updateAuto\) \{' 'if (update.type == "major") {