Add dummy --remote-version argument.

This restores compatibility for ToT generated tryjobs.

BUG=32781
TEST=manual inspection.

Change-Id: I3373854d30bd82030ffa642397ca0a41c96ba372
Reviewed-on: https://gerrit.chromium.org/gerrit/28013
Reviewed-by: Ryan Cui <rcui@chromium.org>
Tested-by: Brian Harring <ferringb@chromium.org>
diff --git a/buildbot/cbuildbot.py b/buildbot/cbuildbot.py
index 2c93035..566b160 100755
--- a/buildbot/cbuildbot.py
+++ b/buildbot/cbuildbot.py
@@ -819,6 +819,9 @@
                    help='Used with manifest logic.  Forces use of this version '
                         'rather than create or get latest.')
 
+  # Added for --remote compatibility against ToT; no-op option.
+  group.add_option('--remote-version', help=optparse.SUPPRESS_HELP)
+
   parser.add_option_group(group)
 
   # Debug options