intertechno: Fix head and tail formatter

The head and tail formatter for the Intertechno gateway were missing a
trailing "0". After adding these, the ITGW-433 can operate a CMR1000.

The corresponding work can be found here:
https://www.instructables.com/Intertechno-LAN-Gateway-ITGW-433-and-OpenHAB/

pyBrematic/gateways/intertechno_gateway.py

@@ -14,8 +14,8 @@ def __init__(self, ip, port=49880):
         # For the Intertechno GWY 433 the parameters look like that:
         # head: "0,0,<repeat>,<pause>,<tune>,<baud>"
         # tail: "<txversion>,<speed>"
-        self.head_format = "0,0,{0},{1},{2},{3}"
-        self.tail_format = "{0},{1}"
+        self.head_format = "0,0,{0},{1},{2},{3},0"
+        self.tail_format = "{0},{1},0"
 
     def build_udp_payload(self, device, action):
         head = self.get_head(device.repeat, device.pause_IT, device.tune, device.baud_IT)