Only notify #wikimedia-qa for browsertests results

All jobs are currently spammed any job configured in Jenkins
(#mediawiki, #wikimedia-dev, #wikimedia-mobile and #wikimedia-qa).

Send to #wikimedia-qa for now.

Only updating jobs that have been created already i.e.:

browsertests-CirrusSearch-en.wikipedia.beta.wmflabs.org-linux-firefox
browsertests-CirrusSearch-test2.wikipedia.org-linux-firefox
browsertests-Translate-meta.wikimedia.org-linux-firefox
browsertests-Translate-sandbox.translatewiki.net-linux-firefox
browsertests-TwnMainPage-sandbox.translatewiki.net-linux-firefox
browsertests-UniversalLanguageSelector-commons.wikimedia.beta.wmflabs.org-linux-firefox
browsertests-UniversalLanguageSelector-sandbox.translatewiki.net-linux-firefox
browsertests-VisualEditor-en.wikipedia.beta.wmflabs.org-linux-firefox

Change-Id: I36a3ca7d1d8ea5fe14f7a57929c6ae148369ab4b