Log Message:
gnutls: Add a dependency to mozilla-rootcerts and configure to use them

Without providing `--with-default-trust-store-file=' configure
argument gnutls try to check a list of hardcoded paths for the
trust store file and use the first found.

If none of them is found gnutls_certificate_set_x509_system_trust()
returns GNUTLS_E_UNIMPLEMENTED_FEATURE and the location of trust
store file should be provided (e.g. in gnutls-cli via --x509cafile
option).

Depends on mozilla-rootcerts and pass `--with-default-trust-store-file='
similarly to security/p11-kit to always have a consistent default
trust store file and an implemented
gnutls_certificate_set_x509_system_trust().

Bump PKGREVISION