The global wiki editability can be set via the web UI, this patch makes
it possible to set the same thing via the API too. This is accomplished
by adjusting the GET and PATCH handlers of the
`/api/v1/repos/{owner}/{repo}` route.
The first will include the property when checking the repo's settings,
the second allows a repo admin to change the setting too.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
df8e58c5cb