FS-2862: fix seg

src/mod/endpoints/mod_sofia/sofia.c

@@ -5959,7 +5959,9 @@ void sofia_handle_sip_i_info(nua_t *nua, sofia_profile_t *profile, nua_handle_t
 		/* Barf if we didn't get our private */
 		assert(switch_core_session_get_private(session));
 		
-		if (!strncasecmp(sip->sip_content_type->c_type, "message", 7) && !strcasecmp(sip->sip_content_type->c_subtype, "update_display")) {
+		if (sip->sip_content_type && 
+			!strncasecmp(sip->sip_content_type->c_type, "message", 7) &&
+			!strcasecmp(sip->sip_content_type->c_subtype, "update_display")) {
 			sofia_update_callee_id(session, profile, sip, SWITCH_TRUE);
 			goto end;
 		}