Fixed issue with packet tracker and msgNO Counter

The packet msgNo field is a string, but is typically is an integer
counter to keep track of a specific packet id.  The counter was
returning an int, but the packet.msgNo is a string.  So, when trying to
delete a packet from the packet tracker, the key for accessing the
packet is the msgNo, which has to be a string.  Passing an int, will
cause the packet tracker to not find the packet, and hence silently
fail.

This patch forces the msgNo counter to be a string.

aprsd/packets/tracker.py

@@ -62,14 +62,6 @@ class PacketTrack(objectstore.ObjectStoreMixin):
     def __len__(self):
         return len(self.data)
 
-    @wrapt.synchronized(lock)
-    def __str__(self):
-        result = "{"
-        for key in self.data.keys():
-            result += f"{key}: {str(self.data[key])}, "
-        result += "}"
-        return result
-
     @wrapt.synchronized(lock)
     def add(self, packet):
         key = packet.msgNo
@@ -78,13 +70,14 @@ class PacketTrack(objectstore.ObjectStoreMixin):
 
     @wrapt.synchronized(lock)
     def get(self, key):
-        if key in self.data:
+        return self.data.get(key, None)
-            return self.data[key]
 
     @wrapt.synchronized(lock)
     def remove(self, key):
-        if key in self.data.keys():
+        try:
             del self.data[key]
+        except KeyError:
+            pass
 
     def restart(self):
         """Walk the list of messages and restart them if any."""

aprsd/utils/counter.py

@@ -37,7 +37,7 @@ class PacketCounter:
     @property
     @wrapt.synchronized(lock)
     def value(self):
-        return self.val.value
+        return str(self.val.value)
 
     @wrapt.synchronized(lock)
     def __repr__(self):