BWA/Fermi submodules need update for GCC 10

[julianhess]

Hi Jeremiah,

New versions of GCC choke on the current bwa/fermi-lite submodules, due to an issue fixed in the following commit: lh3/bwa@2a1ae7b (there is not a complementary commit in fermi-lite, so you have to add the extern keyword yourself in a forked repo).

As a result, SeqLib cannot build on GCC 10. Updating the bwa submodule to its latest version (and manually fixing the fermi-lite submodule) fixes this.

—Julian