Bug 1814414 - Remove unused lines from extensions.properties r=tgiles

Depends on D179835

Differential Revision: https://phabricator.services.mozilla.com/D180141

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

@@ -15,12 +15,9 @@ saveaspdf.saveasdialog.title = Save As
 
 #LOCALIZATION NOTE (newTabControlled.message2) %S is the icon and name of the extension which updated the New Tab page.
 newTabControlled.message2 = An extension, %S, changed the page you see when you open a new tab.
-newTabControlled.learnMore = Learn more
 
 #LOCALIZATION NOTE (homepageControlled.message) %S is the icon and name of the extension which updated the homepage.
 homepageControlled.message = An extension, %S, changed what you see when you open your homepage and new windows.
-homepageControlled.learnMore = Learn more
 
 #LOCALIZATION NOTE (tabHideControlled.message) %1$S is the icon and name of the extension which hid tabs, %2$S is the icon of the all tabs button.
 tabHideControlled.message = An extension, %1$S, is hiding some of your tabs. You can still access all of your tabs from %2$S.
-tabHideControlled.learnMore = Learn more