internal: Ensure queue is at or over max size before dropping (#1399)

Author: brettlangdon

ddtrace/internal/writer.py

@@ -299,7 +299,7 @@ def put(self, item):
             # check qsize value.
             with self.mutex:
                 qsize = self._qsize()
-                if qsize != 0:
+                if qsize >= self.maxsize:
                     idx = random.randrange(0, qsize)
                     self.queue[idx] = item
                     log.warning("Writer queue is full has more than %d traces, some traces will be lost", self.maxsize)