Remove ChainTip copy constructor

scene/3d/skeleton_ik_3d.h

@@ -76,10 +76,6 @@ class FabrikInverseKinematic {
 		ChainTip(ChainItem *p_chain_item, const EndEffector *p_end_effector) :
 				chain_item(p_chain_item),
 				end_effector(p_end_effector) {}
-
-		ChainTip(const ChainTip &p_other_ct) :
-				chain_item(p_other_ct.chain_item),
-				end_effector(p_other_ct.end_effector) {}
 	};
 
 	struct Chain {