Fixed mountPlaylistItem existing media check to be cross-platform.
Fixed mountPlaylistItem existing media check to be cross-platform.

Windows has file:/// before its path, like file:///c:/my/path/video.mp4, whereas Mac has file:// before its path, like file:///Users/josh/video.mp4, where on Mac the first slash is needed for the absolute path.

This patch takes this into account when doing the comparison.

joshuacurtiss/khplaylist,joshuacurtiss/khplaylist