* @param key The configuration key (SRD_CONF_*).
* @param data The new value for the key, as a GVariant with GVariantType
* appropriate to that key. A floating reference can be passed
* @param key The configuration key (SRD_CONF_*).
* @param data The new value for the key, as a GVariant with GVariantType
* appropriate to that key. A floating reference can be passed