Playlist Fix failure to append default file name

FS#12992 - Can't create playlist with all tracks on device (regression)
references this issue

empty_playlist() only sets filename[0] = '\0'
the code was checking filename[1]..
bug ensued

strip extra leading '/' from default path

Change-Id: Ibd8973666ee45583b9e11e3ba317c0e247f085c1
2 files changed