AC_Fence: do not enable altitude fence on Rover by default

libraries/AC_Fence/AC_Fence.cpp

@@ -5,6 +5,12 @@
 
 extern const AP_HAL::HAL& hal;
 
+#if APM_BUILD_TYPE(APM_BUILD_APMrover2)
+#define AC_FENCE_TYPE_DEFAULT AC_FENCE_TYPE_CIRCLE | AC_FENCE_TYPE_POLYGON
+#else
+#define AC_FENCE_TYPE_DEFAULT AC_FENCE_TYPE_ALT_MAX | AC_FENCE_TYPE_CIRCLE | AC_FENCE_TYPE_POLYGON
+#endif
+
 const AP_Param::GroupInfo AC_Fence::var_info[] = {
     // @Param: ENABLE
     // @DisplayName: Fence enable/disable
@@ -19,7 +25,7 @@ const AP_Param::GroupInfo AC_Fence::var_info[] = {
     // @Values: 0:None,1:Altitude,2:Circle,3:Altitude and Circle,4:Polygon,5:Altitude and Polygon,6:Circle and Polygon,7:All
     // @Bitmask: 0:Altitude,1:Circle,2:Polygon
     // @User: Standard
-    AP_GROUPINFO("TYPE",        1,  AC_Fence,   _enabled_fences,  AC_FENCE_TYPE_ALT_MAX | AC_FENCE_TYPE_CIRCLE | AC_FENCE_TYPE_POLYGON),
+    AP_GROUPINFO("TYPE",        1,  AC_Fence,   _enabled_fences,  AC_FENCE_TYPE_DEFAULT),
 
     // @Param: ACTION
     // @DisplayName: Fence Action