Supply --enable-ssh-agent explicitly

In the upstream gnome-keyring, ssh-agent will be disabled by default
in the next release[1].  It would be future proof to supply
--enable-ssh-agent after that, when building with --with ssh_agent.

1. https://gitlab.gnome.org/GNOME/gnome-keyring/-/merge_requests/60

Signed-off-by: Daiki Ueno <dueno@redhat.com>

gnome-keyring.spec

@@ -72,7 +72,9 @@ automatically unlock the "login" keyring when the user logs in.
            --with-systemd \
            --without-libcap-ng \
            --with-pkcs11-config=%{_datadir}/p11-kit/modules \
-%if %{without ssh_agent}
+%if %{with ssh_agent}
+           --enable-ssh-agent
+%else
            --disable-ssh-agent
 %endif