RoSA needs sambamba for testing which needs a patch to htslib to build

[Steffen Möller <steffen_moeller@gmx.de>]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=948919

Hello,

please allow that I bring some attention to this bug report. Are there
any objections to adopt the patch in guix to htslib also for Debian?
This just removes the "static" from cram_to_bam and adds its declaration
to a header file.

Best,

Steffen