Don't even dare check for Fortran

...which can lead to problems when e.g. building against a local trunk GCC
(requiring LD_LIBRARY_PATH) that was configured to build only C/C++ compilers,
so CoinMP's configuration would try to blend that with the system's gfortran.

Change-Id: I9f237df0887e06e50b9e76f3a09cfebb6f22dc20