license: relicense "shared/nm-test-utils-impl.c" under LGPL-2.1+

>>>

  H0=a3e75f329446a93a61ca4c458a7657bd919f4fe6
  commit_has_file() {
      git ls-tree -r "$1" | grep -q "\\s$2"\$
  }
  print_commit_authors() {
      git --no-pager log --full-history --follow --no-merges --pretty='format:<%ae>' $H0 -- "$1" | sort | uniq
  }
  print_blame_authors() {
      local LAST_H

      if commit_has_file $H0 "$1"; then
          LAST_H=$H0
      else
          LAST_H="$(git log --full-history --no-merges -n1 --pretty='format:%H' $H0 -- "$1")"^1
      fi
      git blame --no-progress -C -C -C20 -M -M10 -e "$LAST_H" -- "$1" | sed 's/.*\(<[^>]\+@[^>]\+>\).*/\1/' | sort | uniq
  }
  print_grep() {
      git --no-pager log -p --full-history --follow $H0 -- "$1" | grep -i '[a-z0-9]@\|author\|copyright' | sort | uniq
  }
  prefix() {
      sed "s/^/>>>$1 /"
  }
  collect_all() {
      for F; do
         print_commit_authors "$F" | prefix 1
         echo
         print_blame_authors "$F" | prefix 2
         echo
         print_grep "$F" | prefix 3
      done |
      sort |
      uniq |
      sed 's/@/(at)/'
  }

  collect_all \
      shared/nm-test-utils-impl.c \
      include/nm-test-utils-impl.c \
      libnm-glib/tests/common.c \
      libnm-glib/tests/test-nm-client.c \
      libnm-glib/tests/test-remote-settings-client.c \
      ;

<<<

gives:

>>>1 <bgalvani(at)redhat.com>
>>>1 <biebl(at)debian.org>
>>>1 <danw(at)gnome.org>
>>>1 <danw(at)redhat.com>
>>>1 <dcbw(at)redhat.com>
>>>1 <jklimes(at)redhat.com>
>>>1 <lkundrak(at)v3.sk>
>>>1 <thaller(at)redhat.com>
>>>2 <aleksander(at)aleksander.es>
>>>2 <biebl(at)debian.org>
>>>2 <blueowl(at)centrum.cz>
>>>2 <danw(at)redhat.com>
>>>2 <dcbw(at)redhat.com>
>>>2 <lkundrak(at)v3.sk>
>>>2 <qiaomuf(at)gentoo.org>
>>>2 <rstrode(at)redhat.com>
>>>2 <tambet(at)gmail.com>
>>>2 <thaller(at)redhat.com>
>>>3 [...] Red Hat, Inc.

Everybody in this list agreed to relicensing according to RELICENSE.md.
With exception of <qiaomuf(at)gentoo.org>. However with manual
investigation I think there are no contributions by qiaomuf affected
here. It's only the script that (wrongly) identified the name.

shared/nm-test-utils-impl.c

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
+/* SPDX-License-Identifier: LGPL-2.1+ */
 /*
  * Copyright (C) 2010 - 2015 Red Hat, Inc.
  */