Updating pylint rc file to work with newer versions of pylint

The pylint rc file does not work correctly with newer versions of pylint. The 'disable-msg' key has been modified to be 'disable' in the new versions of pylint.

Leaving both lines in the file to make sure we don't brake anything whilst transitioning over to building in a Centos 6.4 chroot.

Signed-off-by: Rob Dobson <rob@rdobson.co.uk>