Fix Gitlab plugin to extract full branchname when containing slashes
Created by: SRombauts
- convert deprecated split() function into explode() (same parameters)
- use the limit parameter set to 3, to return an array of at most 3 strings, the last one containing everything after the second slash
Example: 'refs/heads/issue/branch-description' => ['refs', 'heads', 'issue/branch-description']