Fix indentation issues reported by flake8

- E121 continuation line under-indented for hanging indent
- E122 continuation line missing indentation or outdented
- E125 continuation line with same indent as next logical line
- E126 continuation line over-indented for hanging indent
- E127 continuation line over-indented for visual indent
- E128 continuation line under-indented for visual indent
- E129 visually indented line with same indent as next logical line
- E131 continuation line unaligned for hanging indent

Fixed automatically with autopep8:

  git ls-files | grep py$ | xargs autopep8 --in-place \
    --select E121,E122,E125,E126,E127,E128,E129,E131

Change-Id: Ifd95fb8e6a1a4d6e9de187b5787d64a6326dd249
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254605
Reviewed-by: Mike Frysinger <vapier@google.com>
Tested-by: David Pursehouse <dpursehouse@collab.net>

subcmds/rebase.py

@@ -43,8 +43,8 @@ branch but need to incorporate new upstream changes "underneath" them.
 
   def _Options(self, p):
     p.add_option('-i', '--interactive',
-                dest="interactive", action="store_true",
-                help="interactive rebase (single project only)")
+                 dest="interactive", action="store_true",
+                 help="interactive rebase (single project only)")
 
     p.add_option('--fail-fast',
                  dest='fail_fast', action='store_true',
@@ -82,7 +82,7 @@ branch but need to incorporate new upstream changes "underneath" them.
             file=sys.stderr)
       if len(args) == 1:
         print('note: project %s is mapped to more than one path' % (args[0],),
-            file=sys.stderr)
+              file=sys.stderr)
       return 1
 
     # Setup the common git rebase args that we use for all projects.