Skip V2 registry and immediately fallback to V1 when mirrors are provided

Since V2 registry does not yet implement mirrors, when mirrors are given automatically fallback to V1 without checking V2 first.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Merge pull request #8901 from dmcgowan/v2_registry_mirror_check

Skip V2 registry and immediately fallback to V1 when mirrors are provided