ArduCopter: turn on INERTIAL_NAV_Z in the config.h file so that it takes...

ArduCopter: turn on INERTIAL_NAV_Z in the config.h file so that it takes effect when built for the mission planner

ArduCopter/config.h

@@ -1149,7 +1149,7 @@
  # define INERTIAL_NAV_XY DISABLED
 #endif
 #ifndef INERTIAL_NAV_Z
- # define INERTIAL_NAV_Z DISABLED
+ # define INERTIAL_NAV_Z ENABLED
 #endif
 
 #endif // __ARDUCOPTER_CONFIG_H__