FS: Use two different speeds when checking for runout

When doing a PAT9125 "soft check", use two different speeds between
retraction and extrusion. This increases the chances that we can
track the surface.

Firmware/fsensor.cpp

@@ -624,7 +624,7 @@ void fsensor_update(void)
 			fsensor_oq_meassure_start(0);
             float e_tmp = current_position[E_AXIS];
             current_position[E_AXIS] -= 3;
-            plan_buffer_line_curposXYZE(200/60, active_extruder);
+            plan_buffer_line_curposXYZE(250/60, active_extruder);
             current_position[E_AXIS] = e_tmp;
             plan_buffer_line_curposXYZE(200/60, active_extruder);
             st_synchronize();