autotest: FETtec tests: give vehicle a chance to realise ESCs are dead

Should remove the race condition where we disable an ESC but the vehicle
doesn't realise and lets the vehicle arm.

Also, waiting this long causes the ESCs to just go missing, not give a
telemetry failure

Tools/autotest/arducopter.py

@@ -7105,21 +7105,24 @@ class AutoTestCopter(AutoTest):
         for mot_id_to_kill in 1, 2:
             self.progress("Turning ESC=%u off" % mot_id_to_kill)
             self.set_parameter("SIM_FTOWESC_POW", mask & ~(1 << mot_id_to_kill))
-            self.assert_prearm_failure("are not sending tel")
+            self.delay_sim_time(1)
+            self.assert_prearm_failure("are not running")
             self.progress("Turning it back on")
             self.set_parameter("SIM_FTOWESC_POW", mask)
             self.wait_ready_to_arm()
 
             self.progress("Turning ESC=%u off (again)" % mot_id_to_kill)
             self.set_parameter("SIM_FTOWESC_POW", mask & ~(1 << mot_id_to_kill))
-            self.assert_prearm_failure("are not sending tel")
+            self.delay_sim_time(1)
+            self.assert_prearm_failure("are not running")
             self.progress("Turning it back on")
             self.set_parameter("SIM_FTOWESC_POW", mask)
             self.wait_ready_to_arm()
 
         self.progress("Turning all ESCs off")
         self.set_parameter("SIM_FTOWESC_POW", 0)
-        self.assert_prearm_failure("are not sending tel")
+        self.delay_sim_time(1)
+        self.assert_prearm_failure("are not running")
         self.progress("Turning them back on")
         self.set_parameter("SIM_FTOWESC_POW", mask)
         self.wait_ready_to_arm()