getLocalMaps() fails when map directory does not exist.

[micheljung]

Caused by: java.nio.file.NoSuchFileException: C:\Users\Peter's\Documents\My Games\Gas Powered Games\Supreme Commander Forged Alliance\maps
at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsDirectoryStream.<init>(Unknown Source)
at sun.nio.fs.WindowsFileSystemProvider.newDirectoryStream(Unknown Source)
at java.nio.file.Files.newDirectoryStream(Unknown Source)
at com.faforever.client.map.MapServiceImpl.getLocalMaps(MapServiceImpl.java:104)
... 77 more