fix git-try broken by CheckCall return type change

git-try

 #!/usr/bin/python
 # Copyright (c) 2009 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """Wrapper for trychange.py for git checkout."""
 
 import logging
 import sys
 
 try:
@@ skipping 12 matching lines @@
 
 
 def GetRietveldPatchsetNumber():
   return GIT.Capture(
       ['config', 'branch.%s.rietveldpatchset' % GIT.GetBranch(None)],
       error_ok=True)[0]
 
 
 def GetRietveldServerUrl():
   return GIT.Capture(
-      ['config', 'rietveld.server'], error_ok=True).strip()
+      ['config', 'rietveld.server'], error_ok=True)[0].strip()
 
 
 if __name__ == '__main__':
   args = sys.argv[:]
   patchset = GetRietveldPatchsetNumber()
   if patchset:
     args.extend([
         '--issue', GetRietveldIssueNumber(),
         '--patchset', patchset,
     ])
   else:
     rietveld_url = GetRietveldServerUrl()
     if rietveld_url:
       args.extend(['--rietveld_url', GetRietveldServerUrl()])
   # Hack around a limitation in logging.
   logging.getLogger().handlers = []
   sys.exit(trychange.TryChange(args, [], False, 'git-try'))