Don't skip lines in beatmap decoding

Was added in cc76c58f5f without any
specific reasoning. Likely not required (and will fix some storyboard
elements inside `.osu` files from not being correctly saved).

osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs

@@ -167,8 +167,6 @@ namespace osu.Game.Beatmaps.Formats
             beatmapInfo.SamplesMatchPlaybackRate = false;
         }
 
-        protected override bool ShouldSkipLine(string line) => base.ShouldSkipLine(line) || line.StartsWith(' ') || line.StartsWith('_');
-
         protected override void ParseLine(Beatmap beatmap, Section section, string line)
         {
             switch (section)