Source the UI with the script provided before checking if voms-proxy-init exists

be committed: # (use "git reset HEAD^1 <file>..." to unstage) # # modified:  src/python/WMCore/Credential/Proxy.py # # Untracked files: # (use "git add <file>..." to
include in what will be committed) # # patch # # It took 8.09 seconds to enumerate untracked files.  'status -uno' # may speed it up, but you have to be careful not to
forget to add # new files yourself (see 'git help status').