Move WebExtensions enabled Add-ons Manager

toolkit/locales/en-US/chrome/mozapps/extensions/update.properties

@@ -1,21 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-mismatchCheckNow=Check Now
-mismatchCheckNowAccesskey=C
-mismatchDontCheck=Don’t Check
-mismatchDontCheckAccesskey=D
-installButtonText=Install Now
-installButtonTextAccesskey=I
-nextButtonText=Next >
-nextButtonTextAccesskey=N
-cancelButtonText=Cancel
-cancelButtonTextAccesskey=C
-statusPrefix=Finished checking %S
-downloadingPrefix=Downloading: %S
-installingPrefix=Installing: %S
-closeButton=Close
-installErrors=%S was unable to install updates for the following add-ons:
-checkingErrors=%S was unable to check for updates for the following add-ons:
-installErrorItemFormat=%S (%S)