Code review comment for lp:~brandontschaefer/unity/support-Og-and-add-O2-compiler-option

Sorry, I did not notice that the old code set CMAKE_CXX_FLAGS_RELEASE to empty. There may be a reason for that (at one time Unity included Compiz's CMake macros which did things of unspeakable evil, for instance). If one can't be found the correct fix is to remove the line altogether. That brings in CMake's default flags for release mode.