Rover: arming checks for GPS use requires_position and velocity

APMrover2/AP_Arming.cpp

@@ -61,7 +61,7 @@ bool AP_Arming_Rover::pre_arm_rc_checks(const bool display_failure)
 // performs pre_arm gps related checks and returns true if passed
 bool AP_Arming_Rover::gps_checks(bool display_failure)
 {
-    if (!rover.control_mode->requires_gps()) {
+    if (!rover.control_mode->requires_position() && !rover.control_mode->requires_velocity()) {
         // we don't care!
         return true;
     }