do not load twice the piloting code, dont override the dragon object

* this are in sync with tenplus1 but with fix due piloting must be before normal dragon
* so dont override the already set dragon object used in normal dragon

dragons/dragon_normal.lua

@@ -1,6 +1,5 @@
 -- 'Generic' dragon
 
-dofile(minetest.get_modpath("mobs_doomed").."/dragons/piloting.lua")
 
 mobs:register_mob("mobs_doomed:dragon", {
    type = "monster",

dragons/main.lua

@@ -1,8 +1,8 @@
 --thanks to diriel, blert2112 and taikedz 
 
-mobs_doomed.dragon = {}
-
-dofile(minetest.get_modpath("mobs_doomed").."/dragons/piloting.lua")
+if not mobs_doomed.dragon then
+	mobs_doomed.dragon = {}
+end
 
 local tamed_dragons = {}
 

init.lua

@@ -97,6 +97,7 @@ end
 -- dragons!! --
 ---------------
 
+dofile(minetest.get_modpath("mobs_doomed").."/dragons/piloting.lua")
 loadmob("dragon_normal","/dragons/")
 if mobs_doomed.dragons then
 	loadmob("main","/dragons/")