Depsgraph: Add missing update tag clear for proxy objects

This was causing proxies updates on every frame, even if they
do not really change. Additionally, it was causing second round
of armature update when used from inside dupligroup (viewport
ensures all objects from dupligroup are up to date before draw).

source/blender/blenkernel/intern/armature_update.c

@@ -702,4 +702,8 @@ void BKE_pose_eval_proxy_copy(EvaluationContext *UNUSED(eval_ctx), Object *ob)
 		printf("Proxy copy error, lib Object: %s proxy Object: %s\n",
 		       ob->id.name + 2, ob->proxy_from->id.name + 2);
 	}
+	/* Rest of operations are NO-OP in depsgraph, so can clear
+	 * flag now.
+	 */
+	ob->recalc &= ~OB_RECALC_ALL;
 }