autobuild: Drop 'py2' flag

This isn't used any more. It was only being set, never referenced.

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
19 jobs for tim-drop-py2 in 169 minutes and 5 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #161833394
docker shared
ctdb

00:43:03

passed #161833372
docker shared
others

00:13:13

passed #161833400
docker private
samba

01:27:18

passed #161872541
private docker
samba-ad-dc

01:14:44

passed #161833386
docker shared
samba-ad-dc-2

00:30:16

passed #161833388
docker shared
samba-ad-dc-backup

00:30:55

passed #161833398
docker shared
samba-ad-dc-ntvfs

01:34:16

passed #161833396
docker shared
samba-ctdb

00:19:49

passed #161833401
docker private
samba-fileserver

00:18:55

passed #161833390
docker shared
samba-libs

00:31:54

passed #161833374
docker shared
samba-none-env

00:47:42

passed #161833376
docker shared
samba-nopython

00:27:00

passed #161833378
docker shared
samba-nopython-py2

00:27:56

passed #161833408
docker private
samba-nt4

00:52:08

passed #161833384
docker shared
samba-o3

00:32:00

passed #161833392
docker shared
samba-static

00:40:44

passed #161833380
docker shared
samba-systemkrb5

00:16:14

passed #161833382
docker shared
samba-xc

00:06:30

canceled #161833406
docker private
samba-ad-dc

02:49:28