3a03d2a33f Qt: load wallet in UI after possible init aborts (Jonas Schnelli)
Pull request description:
Bug was introduced in #13063 (80b4910f7d87983f50047074c3c2397b0a5c4e92) where #13097 made possible to get "hit" by that bug. Reported by @ken2812221 (https://github.com/bitcoin/bitcoin/pull/13097#issuecomment-398445833). Dynamically loading a wallet informs the UI (and therefore makes the instance accessible) about the new wallet before all possible error cases where handled. Easy to reproduce by starting `bitcoin-qt --regtest --nowallet -usehd=0` then in the console enter `loadwallet wallet.dat`. This PR will make sure only correctly initialised (loaded) wallets will appear in the UI.
Backport of Core PR13506
Depends on D4236