adds uptime section for controller

agents/special/agent_unifi_controller

@@ -492,7 +492,7 @@ class unifi_controller(unifi_object):
     def __str__(self):
         _ret = ["<<<unifi_controller:sep(124)>>>"]
         for _k,_v in self.__dict__.items():
-            if _k.startswith("_") or type(_v) not in (str,int,float):
+            if _k == "uptime" or _k.startswith("_") or type(_v) not in (str,int,float):
                 continue
             _ret.append(f"{_k}|{_v}")
 
@@ -503,6 +503,10 @@ class unifi_controller(unifi_object):
             _udm._piggy_back = False
             _ret.append(str(_udm))
 
+        if "uptime" in self.__dict__:
+            _ret.append("<<<uptime>>>")
+            _ret.append(f"{self.uptime}")
+
         _ret.append("<<<labels:sep(0)>>>")
         _ret.append(f"{{\"unifi_device\":\"unifi-{self.type}\"}}")