Fix issues with libwget/ssl_gnutls.c
- libwget/ssl_gnutls.c: Use _config.ocsp_host_cache consistently for hostnames and add null checks for OCSP databases
- include/wget/wget.h: Add option WGET_SSL_OCSP_HOST_CACHE
- src/options.c: Use option WGET_SSL_OCSP_HOST_CACHE
I discovered if (! ocsp_db) return;
type of code in libwget/ocsp.c
hid some issues in libwget/ssl_gnutls.c
.