JENKINS-20201 NPE when saving/updating jobs 

We had a problem after upgrading to version 1.8 on Jenkins 1.536 installed via yum on CentOS-6.4 from http://pkg.jenkins-ci.org/redhat/. We are using this in conjunction with the github-oauth plugin.

When we tried to save or update existing jobs we were getting NPEs calling the GithubProjectProperty.projectUrl, this change returns null in the catch in keeping with the if(tcc.projectUrl == null) check. This PR allows for the ``tpp`` object to be null but also allows ``tpp.profileUrl`` to be null too and behave as the original call did.