29c9e2c2d2 wallet: Do not iterate a directory if having an error while accessing it (Hennadii Stepanov)
Pull request description:
On Windows when `ListDatabases` tries to iterate any system folder, e.g., "System Volume Information", it falls into an infinite loop.
This PR fixes this bug. Now the `debug.log` contains:
```
2021-05-12T09:07:53Z ListDatabases: Access is denied D:/System Volume Information -- skipping.
```
An easy way to reproduce the bug and test this PR is to pass the `-walletdir=D:\` command-line option, and run the `listwalletdir` RPC, or File -> Open Wallet in the GUI menu.
Fixes#20081.
Fixes#21136.
Fixes#21904.
Also https://bitcoin.stackexchange.com/questions/99243/listwalletdir-access-is-denied-d-system-volume-information
ACKs for top commit:
prayank23:
ACK 29c9e2c2d2
promag:
Code review ACK 29c9e2c2d2.
meshcollider:
Code review ACK 29c9e2c2d2
Tree-SHA512: b851c88e6d09626f4cb81acc2fa59a563b2aee64582963285715bf785c64b872e8bf738aa6b27bdbaf4c3e5c8565c2dc2c802135f9aa1f48b4b913435bc5d793