#57 Upgrade quicksilverd to v1.7.6

This proposal aims to upgrade Quicksilver mainnet (quicksilver-2) to v1.7.6 of quicksilverd.\n\nThis release removes the airdrop module, update numerous dependencies, and tidies up a few items prior to upgrade to v0.47. More details have be found here: https://github.com/quicksilver-zone/quicksilver/releases/tag/v1.7.6