update manifest url to production server

[thomasneirynck]

Closes #9970

Use the production server on the feature branches

[thomasneirynck]

jenkins, test this

[thomasneirynck]

failing test is due to lucene issue

[thomasneirynck]

@drewr @spalger @ppisljar could you add an LGTM to this? this updates the Kibana feature branches (5.2 and up) to the new production URL.

[drewr]

LGTM 🎉

[epixa]

@thomasneirynck Why wasn't this done in master?

[thomasneirynck]

@epixa master uses the staging service (tiles-staging.elastic.co). release branches use production (tiles.elastic.co).

#10007 is a follow up to do this automatically, but these services weren't available until very close to 5.2, so we decided to do it manually first.

[epixa]

Thanks for the clarification