Fixed the Ack thread not resending acks

This patch fixes a bug in the AckThread.  The thread loop
was exiting after the first attempt to send the ack.
Thread loops have to return True, in order to be called again
as this is the mechanism in which aprsd gracefully shuts down all
threads.

aprsd/messaging.py

@@ -9,7 +9,7 @@ import re
 import threading
 import time
 
-from aprsd import client, stats, threads, utils
+from aprsd import client, stats, threads, trace, utils
 
 LOG = logging.getLogger("APRSD")
 
@@ -461,25 +461,6 @@ class AckMessage(Message):
             self.id,
         )
 
-    def send_thread(self):
-        """Separate thread to send acks with retries."""
-        cl = client.get_client()
-        for i in range(self.retry_count, 0, -1):
-            log_message(
-                "Sending ack",
-                str(self).rstrip("\n"),
-                None,
-                ack=self.id,
-                tocall=self.tocall,
-                retry_number=i,
-            )
-            cl.sendall(str(self))
-            stats.APRSDStats().ack_tx_inc()
-            # aprs duplicate detection is 30 secs?
-            # (21 only sends first, 28 skips middle)
-            time.sleep(31)
-        # end_send_ack_thread
-
     def send(self):
         LOG.debug("Send ACK({}:{}) to radio.".format(self.tocall, self.id))
         thread = SendAckThread(self)
@@ -506,8 +487,10 @@ class SendAckThread(threads.APRSDThread):
         self.ack = ack
         super().__init__("SendAck-{}".format(self.ack.id))
 
+    @trace.trace
     def loop(self):
         """Separate thread to send acks with retries."""
+        LOG.debug("SendAckThread loop start")
         send_now = False
         if self.ack.last_send_attempt == self.ack.retry_count:
             # we reached the send limit, don't send again
@@ -546,6 +529,7 @@ class SendAckThread(threads.APRSDThread):
             self.ack.last_send_attempt += 1
             self.ack.last_send_time = datetime.datetime.now()
         time.sleep(5)
+        return True
 
 
 def log_packet(packet):