Hi,
I am newby in jenkins,I want to create backup on github using scm sync plugin,I have follow following steps.

1- I have set git global credentials into jenkins GIT option under jenkins configure system->GIT.

2- Installed scm sync plugin and put configuration parameter in jenkins scm sync configuration tab and set repo url git@github.com:username/jenkins_config.git

3 - save

But I am getting below error:
The git-clone command failed. || fatal: destination path '/usr/share/tomcat7/.jenkins/scm-sync-configuration/checkoutConfiguration' already exists and is not an empty directory.