transplant: unnest --stop case

It should be aligned with --continue.

hgext/transplant.py

@@ -692,11 +692,11 b' def _dotransplant(ui, repo, *revs, **opt'
     if opts.get('continue'):
         if not tp.canresume():
             raise error.Abort(_('no transplant to continue'))
-    else:
-        if opts.get('stop'):
+    elif opts.get('stop'):
             if not tp.canresume():
                 raise error.Abort(_('no interrupted transplant found'))
             return tp.stop(ui, repo)
+    else:
         cmdutil.checkunfinished(repo)
         cmdutil.bailifchanged(repo)