The Image API v1 Reference was removed by change
I65ef76fec0029949f8de867d711e745b7aa7f81d. Redirect requests for
api-ref/image/v1/ to the base api-ref/image/ document that contains
a section "What happened to the v1 API?".
Change-Id: I14a49f3809bed9f3e3f02eab9c5b2029907977ac
Closes-bug: #1778579