Apparently the version of openssl available on travis machines does not
support all the ciphersuites expected by compat.sh. While waiting for this
script to handle various openssl versions better, just disable openssl.
Causing spurious fails of ssl-opt.sh. Likely a version issue. It would be
better to investigate the exact problem, and maybe adapt ssl-opt.sh to be
check for a minimum version just as compat.sh does, but this is a quick fix.