Merge pull request 'Fix crash when shooting crystals with rocket arrow' (#2645) from fix_rocket_crystal into master

Reviewed-on: MineClone2/MineClone2#2645
Reviewed-by: PrairieWind <prairie.astronomer1@gmail.com>

mods/ITEMS/mcl_bows/rocket.lua

@@ -20,6 +20,7 @@ end
 
 local function damage_explosion(self, damagemulitplier)
 	local p = self.object:get_pos()
+	if not p then return end
 	mcl_explosions.explode(p, 3, {})
 	local objects = minetest.get_objects_inside_radius(p, 8)
 	for _,obj in pairs(objects) do