emulators/yuzu: prefer OpenSSL over GnuTLS after r560825

• Found NETTLE: /usr/local/lib/libnettle.so
• Found GnuTLS: /usr/local/lib/libgnutls.so
• Found OpenSSL: /usr/lib/libcrypto.so (found version "1.1.1h")

[...]
Error: /usr/local/bin/yuzu is linked to /usr/local/lib/libgnutls.so.30 from security/gnutls but it is not declared as a dependency
Warning: you need LIB_DEPENDS+=libgnutls.so:security/gnutls
Error: /usr/local/bin/yuzu is linked to /usr/local/lib/libnettle.so.8 from security/nettle but it is not declared as a dependency
Warning: you need LIB_DEPENDS+=libnettle.so:security/nettle