[BUG] gallery-dl can't find deviantart folder if its name starts with an underscore

[Miroslav-Cetojevic]

Found a bug where gallery-dl will yell [deviantart][error] NotFoundError: Requested folder could not be found if you enter the URL of a folder that starts with an underscore.

Apparently, the reason for that is the URL replaces underscores in a gallery folder name with dashes (-). My current workaround is to replace said dashes with underscores wherever applicable.

Examples:
Folder: _MtG
URL: deviantart_gallery/-mtg
Result: [deviantart][error] NotFoundError: Requested folder could not be found

Folder: _fantasy_pics
URL: deviantart_gallery/-fantasy-pics
Result: [deviantart][error] NotFoundError: Requested folder could not be found

In both cases, replacing the dashes with underscores in the URL did the trick in command-line.

Seems like something that ought to be fixed.