remove redundant code

lib/model/addressmanager.js

@@ -40,7 +40,7 @@ AddressManager.prototype._incrementIndex = function(isChange) {
 
 AddressManager.prototype.getCurrentAddressPath = function(isChange) {
   return 'm/' +
-    (this.copayerIndex || SHARED_INDEX) + '/' +
+    this.copayerIndex + '/' +
     (isChange ? 1 : 0) + '/' +
     (isChange ? this.changeAddressIndex : this.receiveAddressIndex);
 };