gnu: Don't append '.git' to GitHub uris.

gnu: Don't append '.git' to GitHub uris.

* gnu/packages/admin.scm (nmrpflash)[source]: Remove '.git' from URI.
* gnu/packages/aidc.scm (zxing-cpp),
* gnu/packages/assembly.scm (mbuild),
* gnu/packages/audio.scm (opensles, wildmidi, tinyalsa),
* gnu/packages/browser-extensions.scm (ublock-origin-chromium),
* gnu/packages/check.scm (mutest),
* gnu/packages/compression.scm (unshield),
* gnu/packages/coq.scm (subset),
* gnu/packages/dictionaries.scm (translate-shell),
* gnu/packages/disk.scm (memkind),
* gnu/packages/documentation.scm (latex2html),
* gnu/packages/emacs-xyz.scm (emacs-chronometrist,
  emacs-flycheck-ledger, emacs-counsel-notmuch, emacs-spaceline,
  emacs-org-generate),
* gnu/packages/embedded.scm (ebusd, ebusd-configuration),
* gnu/packages/enchant.scm (nuspell),
* gnu/packages/fontutils.scm (woff2),
* gnu/packages/geo.scm (memphis),
* gnu/packages/gimp.scm (mrg),
* gnu/packages/gnome-xyz.scm (gnome-shell-extension-appindicator),
* gnu/packages/gnome.scm (parlatype),
* gnu/packages/golang.scm (go-github-com-tv42-httpunix,
  go-github-com-ayufan-golang-kardianos-service),
* gnu/packages/graphics.scm (eglexternalplatform, egl-wayland, mmm,
  directfb, flux),
* gnu/packages/gstreamer.scm (openni2, ccextractor, libvisual,
  graphene),
* gnu/packages/guile-xyz.scm (guile-srfi-180, guile-torrent),
* gnu/packages/image.scm (openjpeg-data),
* gnu/packages/java.scm (javacc),
* gnu/packages/language.scm (liblouis, liblouisutdml),
* gnu/packages/linux.scm (pamela, ttyebus),
* gnu/packages/lxqt.scm (lxqt-connman-applet),
* gnu/packages/mail.scm (libetpan),
* gnu/packages/man.scm (ronn),
* gnu/packages/music.scm (tascam-gtk, artyfx),
* gnu/packages/networking.scm (srt, lksctp-tools, nng, nanomsg),
* gnu/packages/python-crypto.scm (pure-python-otr),
* gnu/packages/qt.scm (qtspell),
* gnu/packages/raspberry-pi.scm (raspi-gpio, raspi-open-firmware),
* gnu/packages/rdp.scm (freerdp),
* gnu/packages/ruby.scm (ruby-prawn-templates, ruby-treetop, ruby-gimme,
  ruby-standard, ruby-rubocop-ast, ruby-rexml, ruby-range-compressor,
  ruby-regexp-property-values, ruby-regexp-parser, ruby-rubocop,
  ruby-pdf-reader, ruby-pdf-inspector, ruby-prawn),
* gnu/packages/syncthing.scm (syncthing-gtk),
* gnu/packages/video.scm (svt-hevc, mediasdk, libvideogfx, libde265,
  tslib),
* gnu/packages/xml.scm (libxmlb, libxmlplusplus)[source]: Same.