Instead of checking, if *any* qutebrowser process is running (which may or may not have an IPC socket where we expect it), simply launch a new instance *if socat fails*.
Which it does, if:
* the socket file doesn't exist (qutebrowser simply not running), or
* the socket isn't connectable (qutebrowser crashed, left orphaned socket)
Also put new instances into background, so the script behaves a bit more consistently. (Else it *sometimes* blocks and *sometimes doesn't*, when run.)
Sometimes when qutebrowser crashes, it leaves the IPC socket file behind. In those cases this script still tried to use it, failed, and didn't open your URL at all.
