lua/http: remove bad conversion from URL to file path of VLM input
lua/http: remove bad conversion from URL to file path of VLM input

The conversion is pointless, limiting, unsafe, error-prone and indeed
buggy as it's done in a naive way oblivious of Windows file URL schemes.

Should fix #14842

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc