AP_Scripting: allow AP_SCRIPTING_ENABLED to come from hwdef files

libraries/AP_Scripting/lua_repl.cpp

@@ -2,6 +2,9 @@
 // lua/src/lua.c. It overall modified the functions to the minimum amount
 // required, with the exception of fixing whitespace/indentation on if's
 
+#include "AP_Scripting_config.h"
+
+#if AP_SCRIPTING_ENABLED
 
 #include "lua_scripts.h"
 #include <AP_Scripting/lua_generated_bindings.h>
@@ -257,3 +260,5 @@ void lua_scripts::doREPL(lua_State *L) {
     repl_cleanup();
 }
 
+
+#endif  // AP_SCRIPTING_ENABLED