Git user.name and user.email will now be set to the standard values

  - Gogs
  - gogitservice@gmail.com

if user.name is not set or empty.

If user.name is set and user.email not, it will leave it this way.

`strings.HasPrefix(access.RepoName, uname)` can't handle the situation which like following in access table.

	user_name | repo_name
	----------+-------------
	toby      | toby/blog
	toby      | toby/test
	toby      | tobyzxj/blog
	toby      | tobyzxj/test