When we are not connected and run `/plugins install` we crash because we
get the account struct to check for the (xmpp) tls setting.
To apply that to the http (etc) connection to download the plugin from a
server.
This got introduced in 3a86b8c29 to fix#1624.
There are several ways to handle this (some described in 1880) in this
patch I took the route that it will use secure connection when we are
nto connected and will only check the tls.trust account setting if we
are connected.
Fix https://github.com/profanity-im/profanity/issues/1880
b88174709f