lower TTL for contint websites

Lower TTL from 1H to 300s for the entries:

 doc.wikimedia.org
 integration.wikimedia.org
 doc.mediawiki.org
 integration.mediawiki.org

That in preparation for switching the entries from gallium to the misc
varnish.

Change-Id: I3dea934814036b9e63c4c5c68af3f5844cde1d01
Merge "lower TTL for contint websites"