qisrc rebase: fix some corner cases
qisrc rebase: fix some corner cases

When repository is not clean, we used to call
git rebase --abort which failed with 'no rebase in progress'

Change-Id: I7bec9550d23e9562fef13f5a6a6fb2522b892390

dmerejkowsky/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,aldebaran/qibuild,dmerejkowsky/qibuild,aldebaran/qibuild,aldebaran/qibuild