Prop 877: Substitute IBC light client for doravota

After a hard fork of the doravota chain vota-ash, related to a recently discovered issue in Cosmos-SDK v0.47, all IBC lights on counterparty chains have frozen. During the hard fork, only 4 empty blocks were removed and no transactions were invalidated. This proposal substitutes the previously used IBC light client for doravota. The passing of this proposal is necessary to unblock IBC channels between the two chains that rely on the subject client.