Bug 1647532 - Refactor about:webrtc js code to remove redundant classes. r=ng

Differential Revision: https://phabricator.services.mozilla.com/D81412

toolkit/locales/en-US/chrome/global/aboutWebrtc.properties

@@ -2,11 +2,10 @@
 # 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/.
 
-# LOCALIZATION NOTE (document_title, cannot_retrieve_log):
+# LOCALIZATION NOTE (document_title):
 # The text "WebRTC" is a proper noun and should not be translated.
 # It is the general label for the standards based technology. see http://www.webrtc.org
 document_title = WebRTC Internals
-cannot_retrieve_log = Cannot retrieve WebRTC log data
 
 # LOCALIZATION NOTE (save_page_msg):
 # %1$S will be replaced by a full path file name: the target of the SavePage operation.