Remove outdated email address

Dependencies

• [2] XQ3YV2T3 Don't pollute the source directory
• [3] QNX2BXVA hydra: Improve `AC_INIT' call.
• [4] UHMUHQMU hydra: fix tarball build, add pre suffix to tarballs
• [5] UPRNM2PP configure.ac: Declare we're using the serial test harness
• [6] FV2M6MOT hydra: use autoconf/-make

Change contents

• replacement in configure.ac at line 1
  [3.15951]→[3.0:138](∅→∅)
  − AC_INIT([Hydra], [m4_esyscmd([echo -n $(cat ./version)$VERSION_SUFFIX])],

  − [nix-dev@cs.uu.nl], [hydra], [http://nixos.org/hydra/])
  [3.15951]

  [2.0]
  + AC_INIT([Hydra], [m4_esyscmd([echo -n $(cat ./version)$VERSION_SUFFIX])])