message: Don't GPG sign intermediate commits with github-merge tool
diff: @@ -283,7 +283,7 @@ def main():
  message += '\n\nPull request description:\n\n ' + body.replace('\n', '\n ') + '\n'
  message += get_acks_from_comments(head_commit=subprocess.check_output([GIT,'log','-1','--pretty=format:%H',head_branch]).decode('utf-8')[:6], comments=comments)
  try:
  - subprocess.check_call([GIT,'merge','-q','--commit','--no-edit','--no-ff','-m',message.encode('utf-8'),head_branch])
  + subprocess.check_call([GIT,'merge','-q','--commit','--no-edit','--no-ff','--no-gpg-sign','-m',message.encode('utf-8'),head_branch])
  except subprocess.CalledProcessError:
  print("ERROR: Cannot be merged cleanly.",file=stderr)
  subprocess.check_call([GIT,'merge','--abort'])
  @@ -307,7 +307,7 @@ def main():
  print("ERROR: Unable to compute tree hash")
  sys.exit(4)
  try:
  - subprocess.check_call([GIT,'commit','--amend','-m',message.encode('utf-8')])
  + subprocess.check_call([GIT,'commit','--amend','--no-gpg-sign','-m',message.encode('utf-8')])
  except subprocess.CalledProcessError:
  print("ERROR: Cannot update message.", file=stderr)
  sys.exit(4)
  