Bug 41689: Remove startup.homepage_override_url from Base Browser

Merge Info

Related Issues

• #41689 (closed)

Backport Timeline

• Immediate - patchsets for critical bug fixes or other major blocker (e.g. fixes for a 0-day exploit) OR patchsets with trivial changes which do not need testing (e.g. fixes for typos or fixes easily verified in a local developer build)
• Next Minor Stable Release - patchset that needs to be verified in nightly before backport
• Eventually - patchset that needs to be verified in alpha before backport
• No Backport - patchset for the next major stable

Upstream Merging

• Merge to base-browser - typically for !fixups to patches in the base-browser branch, though sometimes new patches as well
  • NOTE: if your changeset includes patches to both base-browser and tor-browser please please make separate merge requests for each part

Issue Tracking

• Link resolved issues with appropriate Release Prep issue for changelog generation

Change Description

Remove startup.homepage_override_url from Base Browser, and set it in the branding commit, since it's where Firefox customizes these URLs.

While I was at it, I've raised the polling rate of updates: alpha was only 2 hours, definitely too low, so I raised it to 12 hours, to match release (since we have the same update frequency).