git hyper-blame: Fixed --no-default-ignores option to not take argument.

BUG=709835

Change-Id: Ia203cf24adf752ef3acdf660b4fe0990503782b9
Reviewed-on: https://chromium-review.googlesource.com/472587
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
diff --git a/git_hyper_blame.py b/git_hyper_blame.py
index 246ccb2..b24df5f 100755
--- a/git_hyper_blame.py
+++ b/git_hyper_blame.py
@@ -345,6 +345,7 @@
                       type=argparse.FileType('r'), dest='ignore_file',
                       help='a file containing a list of revisions to ignore')
   parser.add_argument('--no-default-ignores', dest='no_default_ignores',
+                      action='store_true',
                       help='Do not ignore commits from .git-blame-ignore-revs.')
   parser.add_argument('revision', nargs='?', default='HEAD', metavar='REVISION',
                       help='revision to look at')