Remove hack to work with mjpegtools 1.9.0rc3 and above and instead use mjpeg_loglev_t...

Remove hack to work with mjpegtools 1.9.0rc3 and above and instead use mjpeg_loglev_t() for getting the log levels. C...

Original commit message from CVS:
Based on a patch by:
Hans de Goede <j dot w dot r dot degoede at hhs dot nl>
* configure.ac:
* ext/mpeg2enc/gstmpeg2enc.cc:
Remove hack to work with mjpegtools 1.9.0rc3 and above and instead
use mjpeg_loglev_t() for getting the log levels. Check for this
function in configure.ac as the pkg-config file doesn't tell us
which release candidate we have. Fixes bug #517896.