Fix help string typo.

Bug:
Change-Id: Id7509ae08bc09c6cb291f29b55c60d6d96e79121
Reviewed-on: https://chromium-review.googlesource.com/721359
Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: David Benjamin <davidben@chromium.org>

gclient.py

@@ -2201,7 +2201,7 @@ def CMDconfig(parser, args):
   parser.add_option('--name',
                     help='overrides the default name for the solution')
   parser.add_option('--deps-file', default='DEPS',
-                    help='overrides the default name for the DEPS file for the'
+                    help='overrides the default name for the DEPS file for the '
                          'main solutions and all sub-dependencies')
   parser.add_option('--unmanaged', action='store_true', default=False,
                     help='overrides the default behavior to make it possible '