`ctanurl` doen't produce an output

With an up-to-date MiKTeX the entry

https://github.com/rolfn/dtk/blob/3a0ecb7f9ea33105c6d1e0d61034b0047af33d02/beispiel.bib#L18-L25

does not produce an URL output. When I change ctanurl to (just) url it seems to work. Is that a bug?

\begin{filecontents}{beispiel.bib}
@Book{voss:2012,
  author    = {Herbert Voß},
  title     = {PSTricks --  Grafik für {\TeX} und {\LaTeX}},
  edition   = {6},
  publisher = {DANTE -- Lehmanns Media},
  date      = {2012},
  address   = {Heidelberg/""Berlin}
}

@ctan{pakin:2008,
  Title          = {The Comprehensive {\LaTeX} Symbol list},
  Author         = {Pakin, Scott},
  Organization   = {CTAN},
  url        = {/info/symbols/comprehensive/symbol-a4.pdf},
  date           = {2008},
}

@ctan{europecv,
  author = {Nicola Vitacolonna},
  sorttitle={europecv},
  title = {\texttt{europecv}: an unofficial class for European curricula},
  ctanurl = {macros/latex/contrib/europecv/},
  date = {2006-04-24},
  urldate = {2016-03-07},
}

@online{ep1,
  author = {Bundesinstitut für Berufsbildung},
  sortname ={Bundesinstitut},
  title = {\texttt{europass} Deutschland},
  sorttitle={europass},
  url = {http://www.europass-info.de},
  urldate = {2016-03-07}
}
\end{filecontents}
\documentclass{dtk}
\usepackage{hyperref}
    \addbibresource{beispiel.bib}
\begin{document}
    \LaTeX3
        \nocite{*}
    \printbibliography
\end{document}

result showing the output of above code

Mit

\begin{filecontents}[force]{beispiel.bib}
    @Book{voss:2012,
        author  = {Herbert Voß},
        title       = {PSTricks --  Grafik für {\TeX} und {\LaTeX}},
        edition = {6},
        publisher   = {DANTE -- Lehmanns Media},
        date        = {2012},
        address = {Heidelberg/""Berlin}
    }

    @online{ep1,
        author = {Bundesinstitut für Berufsbildung},
        sortname ={Bundesinstitut},
        title = {\texttt{europass} Deutschland},
        sorttitle={europass},
        url = {http://www.europass-info.de},
        urldate = {2016-03-07}
    }
\end{filecontents}
\documentclass{dtk}
\usepackage{hyperref}
\addbibresource{beispiel.bib}
\addbibresource[location=remote]{http://mirrors.ctan.org/biblio/ctan-bibdata/ctan.bib}

\begin{document}
    \LaTeX3
    baz\cite{voss:2012} bee\cite{ep1} foo\cite{ctan-comprehensive} bar\cite{ctan-europecv}
    \printbibliography
\end{document}

bekommen wir:

rolfn / dtk

`ctanurl` doen't produce an output #20