Update uc2rest/motor.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: beniroquai

uc2rest/motor.py

@@ -549,7 +549,7 @@ def move_stepper(self, steps=(0,0,0,0), speed=(1000,1000,1000,1000), is_absolute
         self.isRunning = True
         is_blocking = not self._parent.is_wifi and is_blocking and self._parent.serial.is_connected
         timeout = timeout if is_blocking else 0
-        nResponses = len(payload["motor"])+1
+        nResponses = len(payload["motor"]["steppers"]) + 1
         # if we get a return, we will receive the latest position feedback from the driver  by means of the axis that moves the longest
         r = self._parent.post_json(path, payload, getReturn=is_blocking, timeout=timeout, nResponses=nResponses)