Add rtpengine configuration parameter

The rtpengine configuration parameter was documented in the XML documentation,
but it was not actually registered with the sorcery object. This adds the
parameter with a default of "asterisk", such that res_rtp_asterisk is chosen as
the default RTP implementation.

(closes issue ASTERISK-22380)
Reported by: Rusty Newton
Tested by: Rusty Newton
........

Merged revisions 397621 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@397622 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_pjsip/pjsip_configuration.c

@@ -699,6 +699,7 @@ int ast_res_pjsip_initialize_configuration(void)
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "fromuser", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, fromuser));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "fromdomain", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, fromdomain));
 	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "mwifromuser", "", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, subscription.mwi.fromuser));
+	ast_sorcery_object_field_register(sip_sorcery, "endpoint", "rtpengine", "asterisk", OPT_STRINGFIELD_T, 0, STRFLDSET(struct ast_sip_endpoint, media.rtp.engine));
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "dtlsverify", "", dtls_handler, NULL, 0, 0);
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "dtlsrekey", "", dtls_handler, NULL, 0, 0);
 	ast_sorcery_object_field_register_custom(sip_sorcery, "endpoint", "dtlscertfile", "", dtls_handler, NULL, 0, 0);