gs_usb: treat timeout=None as forever

pass '0' when timeout=None (as proposed by @zariiii9003
 in hardbyte#2026 (comment))

Author: BenGardiner

can/interfaces/gs_usb.py

@@ -175,7 +175,7 @@ def _recv_internal(self, timeout: float | None) -> tuple[can.Message | None, boo
         frame = GsUsbFrame()
 
         # Do not set timeout as None or zero here to avoid blocking
-        timeout_ms = round(timeout * 1000) if timeout else 1
+        timeout_ms = round(timeout * 1000) if timeout else 0
         if not self.gs_usb.read(frame=frame, timeout_ms=timeout_ms):
             return None, False