Set gitweb.owner in the config on repo create

[michaelowens]

Is your feature request related to a problem? Please describe.
n/a

Describe the solution you'd like
When creating a repo it would be nice to set the gitweb.owner config variable.

Describe alternatives you've considered
n/a

Additional context
#256
It was mentioned here, and the commit says it writes the owner, but it seems to be missing from the code.

Gitweb documentation: https://git-scm.com/docs/gitweb#Documentation/gitweb.txt-gitwebowner

[ThaLuffy]

+1

[dvrd]

This is already implemented in the fork at https://github.com/dvrd/soft-serve — pkg/backend/repo.go:91 sets gitweb.owner to the repo creator's username on repository creation.