In this commit, we update our btcwallet dependency to point to the
latest version. This latest version redefines what the wallet will
consider as an initial sync. We'll now define it by determining if the
wallet has synced up to its birthday block, rather than looking at the
number of UTXOs in the wallet. This was needed, especially for light
clients, because it would cause unnecessary rescans to happen from the
wallet's birthday if the wallet had no UTXOs.
The main ltcd repo has been force pushed, which removed the commit that we pinned against prior. In this commit, we update to the latest version of ltcd.
