Import Debian changes 1.2.6-2

network-manager-l2tp (1.2.6-2) unstable; urgency=medium

  * Drop obsolete Build-Depends on libdbus-glib-1-dev.
    It is no longer required after the port to GDBus
  * Drop redundant Build-Depends on dh-autoreconf and --with autoreconf
    They are enabled by default with compat level 10
  * Drop unnecessary Breaks and Replaces network-manager-l2tp-gnome (<< 1.2.4)
  * Added missing LGPL-2+ and CC0-1.0 to copyright file