Hi,

Running lintian can put down a considerable load on the machine,
especially if it's a slow one or when the package is large.

Given the presumed "begginer users" target of gdebi, I guess it's
unlikelly that many of them would even look at the "Lintian" tab.

So, to remove that "unnecessary" load, patch attached defers running
lintian on startup until it's tab is selected.

Cheers!
Filip
Debian Release: 9.0
   500 trusty          ppa.launchpad.net   500 stretch-loki
gandalfn.ovh   500 stable          security.debian.org   500 stable
     repo.vivaldi.com   500 stable          httpredir.debian.org   500
stable          dl.winehq.org   500 all             liveusb.info  1050
stretch         angband.pl   100 stretch-backports httpredir.debian.org
    1 experimental    ftp.debian.org
--- Package information. ---
Depends                     (Version) | Installed
=====================================-+-=================
python3:any             (>= 3.3.2-2~) | gdebi-core           (=
0.9.5.7+nmu1) | 0.9.5.7+nmu1
gir1.2-gtk-3.0                        | 3.22.11-1
gir1.2-vte-2.91                       | 0.46.1-1
python3-gi                            | 3.22.0-2
gksu                                  | 2.0.2-9+b1
gnome-icon-theme                      | 3.12.0-2


Recommends            (Version) | Installed
===============================-+-===========
libgtk2-perl                    | 2:1.2499-1
shared-mime-info                | 1.8-1
lintian                         | 2.5.50.4


Package's Suggests field is empty.