增加redis通知方式向设备/平台发送报警消息功能

src/main/java/com/genersoft/iot/vmp/gb28181/utils/SipUtils.java

@@ -25,6 +25,7 @@ public class SipUtils {
      * */
     public static String getChannelIdFromHeader(Request request) {
         Header subject = request.getHeader("subject");
+        if (subject == null) return null;
         return ((Subject) subject).getSubject().split(":")[0];
     }