Use label hasBrowserTests for browser tests

integration-selenium-driver has been deleted, it is replaced by the
label hasBrowserTests which is applied on labs slaves.

Updates jobs:
    mwext-browsertests-CirrusSearch-phantomjs
    mwext-browsertests-Flow-firefox
    mwext-browsertests-Flow-phantomjs
    mwext-browsertests-MobileFrontend-firefox
    mwext-browsertests-MobileFrontend-phantomjs
    mwext-browsertests-Translatewiki-firefox
    mwext-browsertests-Translatewiki-phantomjs
    mwext-browsertests-UniversalLanguageSelector-firefox
    mwext-browsertests-UniversalLanguageSelector-phantomjs
    mwext-browsertests-VisualEditor-firefox
    mwext-browsertests-VisualEditor-phantomjs
    qa-browsertests-build
    qa-browsertests-postmerge
    qa-browsertests-run

Change-Id: I2676620e3c56bbd6ab2650853b3b4cf5c9f2ed20