Med: libcrmcommon: Disable FIPS mode when running md5sum check.

MD5 is not a supported algorithm when FIPS is enabled. Luckily, we are
not using it for any security purposes - only for calculating hashes of
XML blobs. In order to use the MD5 algorithm, we have to temporarily
disable and then re-enable the FIPS check in gnutls which provides
macros for this purpose.

We were previously not seeing this problem because we were using gnulib,
which is not FIPS aware. The switch to gnutls causes the problem.

Tested by running "make check" on a system that was installed with the
fips=1 kernel command line parameter, which resulted in a segfault. The
addition of this patch causes the check to succeed.