Don't prompt the user for name/email unless necessary

If the user has already configured a workspace, use these values
when re-running 'repo init'.

Otherwise, if the user has global name and e-mail set, use these.

It's always possible to override this and be prompted by specifying
--config-name when running 'repo init'.

Change-Id: If45f0e4b14884071439fb02709dc5cb53f070f60
2 files changed