referenced version of libpng (libpng-1.4.1.tar.gz) not available

[billspat]

script terminates with "Failed download: ftp://ftp.simplesystems.org/pub/libpng/png/src/libpng-1.4.1.tar.gz, size: B, aborting."

libpng-1.4.1.tar.gz is no longer available on ftp://ftp.simplesystems.org, however

ftp://ftp.simplesystems.org/pub/libpng/png/src/libpng-1.4.1.tar.gz is available and editing the install script fixes the issue (I'm new and don't know the correct way to patch here...)