Fixes #55

[FIX] Changed socket out to be a reference to socket in for RTPClient.
      Some systems were just replying to the port they were receiving RTP on
      instead of sending RTP to the port specified in the SDP of the INVITE or
      OK message. This was causing loss of audio and DTMF on those systems.

pyVoIP/RTP.py

@@ -336,7 +336,9 @@ def __init__(
 
     def start(self) -> None:
         self.sin = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-        self.sout = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        # Some systems just reply to the port they receive from instead of
+        # listening to the SDP.
+        self.sout = self.sin
         self.sin.bind((self.inIP, self.inPort))
         self.sin.setblocking(False)