Error message for space in branch name

I put a space in the branch name and I get some random error message but the error message should say “No spaces allowed in branch names” instead. I know this isn't common but the more non-technical users we get, the more this is going to happen.

cc: @JobV

Milestone changed to 8.3

What about automatically replacing spaces with hyphens?

Also a great solution.

mentioned in merge request !1714 (closed)

Thanks @razer6

Reassigned to @dbalexandre

mentioned in merge request !2122 (merged)

Status changed to closed by merge request !2122 (merged)

mentioned in commit 6b968a8f

mentioned in issue #19756 (closed)

Mentioned in issue #24528 (closed)