Improve compilation with dante socks5 support by looking for "-lsocksd"

[Jonher937]

Hi, I recently attempted to compile lftp on Ubuntu focal with socks5 support via dante library. Ubuntu provides libdsocksd0 that installs:

/usr/lib/x86_64-linux-gnu/libdsocksd.so.0
/usr/lib/x86_64-linux-gnu/libdsocksd.so.0.0.0

If you attempt to run ./configure --with-socksdante if will fail as it's trying to -lsocks and not -lsocksd. https://github.com/lavv17/lftp/blob/285c61cacb8ec0177a0b60224343dac2ec8af6b8/configure.ac#L205

If however I compile dante manually and do a make install on dante it will install the libs into /usr/local/lib with libsocks as the name and will then successfully compile.

Could this be improved so that -lsocksd is also acceptable when --with-socksdante is used?