fix oauth2decorator user_agent regression #5007043
fix oauth2decorator user_agent regression #5007043

clancychilds/oauth2client,google/oauth2client,googleapis/google-api-python-client,jonparrott/oauth2client,jonparrott/oauth2client,googleapis/oauth2client,googleapis/google-api-python-client,googleapis/oauth2client,google/oauth2client,clancychilds/oauth2client