remove christoph's middle initial (he was the last one left with one)

.mailmap

@@ -5,7 +5,6 @@ Thomas Kloss <kloss@itp.uni-frankfurt.de>
 Tómas Örn Rosdahl <torosdahl@gmail.com>
 <slavoutich@ostroukh.me> <ostroukh@lorentz.leidenuniv.nl>
 <m.t.wimmer@tudelft.nl> <wimmer@lorentz.leidenuniv.nl>
-Christoph W. Groth <christoph.groth@cea.fr>
 Dániel Varjas <dvarjas@gmail.com>
 Pablo Pérez Piskunow <pablo.perez.piskunow@gmail.com>
 Michał Nowak <albeercik@gmail.com>

AUTHORS.rst

@@ -6,7 +6,7 @@ The Kwant authors can be reached at authors@kwant-project.org.
 
 The principal developers of Kwant are
 
-* `Christoph W. Groth <mailto:christoph.groth@cea.fr>`_ (CEA Grenoble)
+* `Christoph Groth <mailto:christoph.groth@cea.fr>`_ (CEA Grenoble)
 * `Michael Wimmer <https://michaelwimmer.org>`_ (TU Delft)
 * `Anton Akhmerov <http://antonakhmerov.org>`_ (TU Delft)
 * `Xavier Waintal <http://inac.cea.fr/Pisp/xavier.waintal>`_ (CEA Grenoble)