Convert error for firefox.png #18
Description
The command make fails with the following error:
convert tmp/firefox.png .mlvwm/pixmap/firefox.xpm
WARNING: The convert command is deprecated in IMv7, use "magick" instead of "convert" or "magick convert"
convert: improper image header `tmp/firefox.png' @ error/png.c/ReadPNGImage/3947.
convert: no images defined `.mlvwm/pixmap/firefox.xpm' @ error/deprecate.c/ConvertImageCommand/3368.
make: *** [Makefile:30: pixmap] Error 1
After some investigation it appears that the download link for firefox.png is broken
