Consider updating MAR_CHANNEL_ID for nightly build (and maybe alpha too)
tor-browser.git) we currently set
torbrowser-torproject-release in all cases.
I see that Mozilla is using a different
MAR_CHANNEL_ID for each of their channel (previously by updating
browser/confvars.sh, and now by setting it from taskcluster: https://hg.mozilla.org/releases/mozilla-release/rev/66f52bda7e14e26235bd0a43bb68ad11775046e4).
So I am wondering if we should do the same, and use a different
MAR_CHANNEL_ID for nightly, and maybe for the alpha too.