On my Linux Mint 19.1:
```bash
$ umask
0022
```

After the first run of `bitcoin-qt -sysperm=false` the `0700` permissions are expected for both the datadir (`~/.bitcoin`) and the walletdir (`~/.bitcoin/wallets`).

Actually, the directories are created with such access permissions:
```bash
$ stat ~/.bitcoin | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
$ stat ~/.bitcoin/wallets | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
```

Refs:
- #4286
- #13371
- #13389

NOTE: reading through the initial PR #4286 makes me think it was controversial. Is it a better and simpler way to just get rid of `-sysperm` option? I believe a user who needs this option can easily run `chown` command.
{
    LOCK(cs_args);
    fs::path& path = net_specific ? m_cached_network_datadir_path : m_cached_datadir_path;
    
    
    if (!path.empty()) return path;
    const fs::path datadir{GetPathArg("-datadir")};
    if (!datadir.empty()) {
        path = fs::absolute(datadir);
        if (!fs::is_directory(path)) {
            path = "";
            return path;
        }
    } else {
        path = GetDefaultDataDir();
    }
    if (!fs::exists(path)) {
        fs::create_directories(path / "wallets");
    }
    if (net_specific && !BaseParams().DataDir().empty()) {
        path /= fs::PathFromString(BaseParams().DataDir());
        if (!fs::exists(path)) {
            fs::create_directories(path / "wallets");
        }
    }
    return path;
}
void ArgsManager::ClearPathCache()