Bug 1532554 - point directly at beta release notes from beta builds r=glandium

Instead of relying on a server-side redirect from XX.0 to XX.0beta,
change the URL to be the right one for beta and developer edition
builds, like fennec already does in mobile/android/app/mobile.js.

Differential Revision: https://phabricator.services.mozilla.com/D22065

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

browser/branding/aurora/pref/firefox-branding.js

@@ -18,7 +18,7 @@ pref("app.update.url.manual", "https://www.mozilla.org/firefox/aurora/");
 // supplied in the "An update is available" page of the update wizard.
 pref("app.update.url.details", "https://www.mozilla.org/firefox/aurora/");
 
-pref("app.releaseNotesURL", "https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew");
+pref("app.releaseNotesURL", "https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew");
 
 // The number of days a binary is permitted to be old
 // without checking for an update.  This assumes that

browser/branding/official/pref/firefox-branding.js

@@ -17,12 +17,12 @@ pref("app.update.promptWaitTime", 691200);
 #if MOZ_UPDATE_CHANNEL == beta
 pref("app.update.url.manual", "https://www.mozilla.org/firefox/beta");
 pref("app.update.url.details", "https://www.mozilla.org/%LOCALE%/firefox/beta/notes");
+pref("app.releaseNotesURL", "https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew");
 #else
 pref("app.update.url.manual", "https://www.mozilla.org/firefox/");
 pref("app.update.url.details", "https://www.mozilla.org/%LOCALE%/firefox/notes");
-#endif
-
 pref("app.releaseNotesURL", "https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew");
+#endif
 
 // The number of days a binary is permitted to be old
 // without checking for an update.  This assumes that