make mediawiki jobs runnable on slaves

Updated the git scm macro git-mwcore-nosubmodules to fetch from
http://integration.wikimedia.org/zuul/git/* using the local Gerrit
replication for reference.

Jobs updated:
mediawiki-core-doxygen-publish
mediawiki-core-install-sqlite
mediawiki-core-jsduck
mediawiki-core-jsduck-publish
mediawiki-core-lint
mediawiki-core-phpunit-api
mediawiki-core-phpunit-databaseless
mediawiki-core-phpunit-misc
mediawiki-core-phpunit-parser
mediawiki-core-qunit
mediawiki-core-regression-REL1_19
mediawiki-core-regression-REL1_20
mediawiki-core-regression-REL1_21
mediawiki-core-regression-master
mediawiki-core-whitespaces

Change-Id: I924a8c5531d7059a0850e7d5295d33a3ba8861b1