fix find version for libjpeg-turbo
Review Request #121221 - Created Nov. 23, 2014 and discarded
Clear CMAKE_MATCH_1 var, to compile with libjpeg-turbo
When the regexp for jpeglib.h is not found (libjpeg-turbo case), the CMAKE_MATCH_0 and CMAKE_MATCH_1 var still with old value, and the old value, in this case was 2060 (lcms version).
reseting the var before trying to find the version fix this bug.