When we perform commit without staged changes we will get an error.
If it is needed to change the message of last commit we should allow
to do it, even if there are no staged changes.
JGit does not support HTTP 301 redirects yet, it throws exception when
performing commands with remote using http url instead https.
Native git can do it.
1. Fix storing issue in JGitConfigImpl
2. Commit command scenario - Get gerrit changid property from configuration
and set the commit command to set insert change ID to work with Gerrit
3. Push command scenario - Create PushResponse with details regarding updates
and refs and use it in push command
Change-Id: Ic54109810cdc6ba026447f691759ef0fc94924d0
Signed-off-by: Offer Shostak <offershostak@gmail.com>