Removed X-DfltLang & X-DfltPage from zero VCLs

Depended on these two patches, both of which are now live:
 -- https://gerrit.wikimedia.org/r/#/c/97107/
 -- https://gerrit.wikimedia.org/r/#/c/97115/

All default language redirection for home pages
should be handleded as redirects by the backend

Change-Id: I75462edb12bfcdab18f7589aaa0a2901c4041b40
Merge "Removed X-DfltLang & X-DfltPage from zero VCLs" into production