Bug 1486211 - Remove unused key browser.search.defaultenginename from region.properties r=mkaply

Differential Revision: https://phabricator.services.mozilla.com/D4419

--HG--
extra : moz-landing-system : lando

mobile/locales/en-US/chrome/region.properties

@@ -2,10 +2,7 @@
 # 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/.
 
-# This preference is only used to generate browsersearch.json.
-browser.search.defaultenginename=Google
-
-# increment this number when anything gets changed in the list below.  This will
+# Increment this number when anything gets changed in the list below.  This will
 # cause Firefox to re-read these prefs and inject any new handlers into the
 # profile database.  Note that "new" is defined as "has a different URL"; this
 # means that it's not possible to update the name of existing handler, so