make wikis public by default to forbid bots to put content

Signed-off-by: Thomas Citharel <tcit@tcit.fr>
2 jobs for close-wikis in 8 minutes and 4 seconds (queued for 46 seconds)
Status Job ID Name Coverage
  Test
passed #41550
test_php7.0

00:05:31

passed #41551
test_php7.1

00:04:22