Broken link to test data in bufr package

[kylehilburn]

I was building the hpc-stack, and ran into problems with the bufr library. The problem was that in: hpc-stack/pkg/bufr-bufr_v11.5.0/test/CMakeLists.txt, there was a reference to https://ftp.emc.ncep.noaa.gov/static_files/public/bufr.tar, which no longer exists. I substituted bufr-11.6.0.tgz and everything built successfully.