Fix missing _node_protocols check

Author: bouwew

plugwise_usb/nodes/circle.py

@@ -903,14 +903,15 @@ async def clock_synchronize(self) -> bool:
             self._mac_in_str,
             int(abs(clock_offset.total_seconds())),
         )
+        return await self._send_clock_set_req()
+
+    async def _send_clock_set_req(self) -> bool:
+        """Send CircleClockSetRequest."""
         if self._node_protocols is None:
             raise NodeError(
                 "Unable to synchronize clock when protocol version is unknown"
             )
-        return await self._send_clock_set_req()
 
-    async def _send_clock_set_req(self) -> bool:
-        """Send CircleClockSetRequest."""
         set_request = CircleClockSetRequest(
             self._send,
             self._mac_in_bytes,