Update GObject getvotes RPC output

Update [GObject getvotes RPC](https://dash-docs.github.io/en/developer-reference#gobject-getvotes) example with shortened MN Outpoint when dashpay/dash#1871 is released

Source File: _includes/devdoc/dash-core/rpcs/rpcs/gobject.md