Rover: reduce arming delay to 2 sec

APMrover2/config.h

@@ -60,6 +60,9 @@
   #define MAV_SYSTEM_ID    1
 #endif
 
+#ifndef ARM_DELAY_MS
+  #define ARM_DELAY_MS  2000
+#endif
 
 //////////////////////////////////////////////////////////////////////////////
 // FrSky telemetry support

APMrover2/radio.cpp

@@ -64,7 +64,7 @@ void Rover::rudder_arm_disarm_check()
             const uint32_t now = millis();
 
             if (rudder_arm_timer == 0 ||
-                now - rudder_arm_timer < 3000) {
+                now - rudder_arm_timer < ARM_DELAY_MS) {
                 if (rudder_arm_timer == 0) {
                     rudder_arm_timer = now;
                 }
@@ -83,7 +83,7 @@ void Rover::rudder_arm_disarm_check()
             const uint32_t now = millis();
 
             if (rudder_arm_timer == 0 ||
-                now - rudder_arm_timer < 3000) {
+                now - rudder_arm_timer < ARM_DELAY_MS) {
                 if (rudder_arm_timer == 0) {
                     rudder_arm_timer = now;
                 }