增加zlm代理的secret自动添加， 增加配置文件的默认值，缺少非关键参数不会无法启动，简化配置文件给新手带来的压力，前端使用wvp代理流。

src/main/java/com/genersoft/iot/vmp/gb28181/bean/Device.java

@@ -68,6 +68,12 @@ public class Device {
 	 */
 	private Long registerTimeMillis;
 
+
+	/**
+	 * 心跳时间
+	 */
+	private Long KeepaliveTimeMillis;
+
 	/**
 	 * 通道个数
 	 */
@@ -176,4 +182,12 @@ public class Device {
 	public void setRegisterTimeMillis(Long registerTimeMillis) {
 		this.registerTimeMillis = registerTimeMillis;
 	}
+
+	public Long getKeepaliveTimeMillis() {
+		return KeepaliveTimeMillis;
+	}
+
+	public void setKeepaliveTimeMillis(Long keepaliveTimeMillis) {
+		KeepaliveTimeMillis = keepaliveTimeMillis;
+	}
 }