FreeBSD CI: quit freebsd-11-3-snap
testing on a single FreeBSD version is enough.  `-snap` images are
unstable to perform CI test.
@@ -12,8 +12,6 @@ FreeBSD_task:
matrix:
freebsd_instance:
image_family: freebsd-12-1
- freebsd_instance:
- image_family: freebsd-11-3-snap
prepare_script:
- pkg install -y cmake git $SSL
- git submodule update --init --recursive
