AR_Motors: remove arming check to allow ackerman and skid-steering

libraries/AR_Motors/AP_MotorsUGV.cpp

@@ -454,16 +454,6 @@ bool AP_MotorsUGV::output_test_pwm(motor_test_order motor_seq, float pwm)
 //  returns true if checks pass, false if they fail.  report should be true to send text messages to GCS
 bool AP_MotorsUGV::pre_arm_check(bool report) const
 {
-    // check if both regular and skid steering functions have been defined
-    if (SRV_Channels::function_assigned(SRV_Channel::k_throttleLeft) &&
-        SRV_Channels::function_assigned(SRV_Channel::k_throttleRight) &&
-        SRV_Channels::function_assigned(SRV_Channel::k_throttle) &&
-        SRV_Channels::function_assigned(SRV_Channel::k_steering)) {
-        if (report) {
-            gcs().send_text(MAV_SEVERITY_CRITICAL, "PreArm: regular AND skid steering configured");
-        }
-        return false;
-    }
     // check if only one of skid-steering output has been configured
     if (SRV_Channels::function_assigned(SRV_Channel::k_throttleLeft) != SRV_Channels::function_assigned(SRV_Channel::k_throttleRight)) {
         if (report) {