fwupd: do fwupd_client_connect before setting user agent

Since fwupd 1.8.11, setting user agent before doing anything else causes an error, because the daemon version is not yet set and the user agent setting function now errors out if that's the case (previously it set part of the user agent string as NULL, which was bad and apparently confused LVFS). gnome-software does client_connect (well, it uses the async version) before setting the user agent, so let's try that.

Signed-off-by: Adam Williamson awilliam@redhat.com