kdePackages.kdoctools: use default outputs

mkKdeDerivation {

  pname = "kdoctools";

  # lots of self-references, the output is pretty small (~5MB), not worth trying to untangle

  outputs = ["out"];

  # Perl could be used both at build time and at runtime.

  extraNativeBuildInputs = [perl perlPackages.URI];

  extraBuildInputs = [docbook_xml_dtd_45 docbook-xsl-nons];