When attempting to compile plpftp, sisinstall and other plptools on Haiku, linking fails due to missing symbols.

For example. plpftp fails with undefined reference errors for getservbyname and endservent (plpftp/main.cc, lines 142 and 143 respectively).

This can be worked around by explicitly adding -lnetwork to the relevant LDADD variable in each Makefile.am, but I'm sure there's a "proper" way to do this.