client: add missing "," in option list
client: add missing "," in option list

In commit 44073d1b38e2 - client: improve WAN option description
one "," was missing at the end of the line. Since the next argument
was a string too, gcc silently concatenated them, and thanks to C++
polymorphic functions, the compiler didn't complain about the
missing argument, so it went unnoticed.
The effects are pretty bad though, since it prevents spicec from
running because it thinks command line parsing fails.

dezelin/spice,elmarco/spice,elmarco/spice,Fantu/spice,dezelin/spice,mathslinux/spice,ya-mouse/spice,Fantu/spice,Fantu/spice,freedesktop-unofficial-mirror/spice__spice,freedesktop-unofficial-mirror/spice__spice,dezelin/spice,Fantu/spice,alon/spice-server,freedesktop-unofficial-mirror/spice__spice,alon/spice-server,elmarco/spice,mathslinux/spice,dezelin/spice,freedesktop-unofficial-mirror/spice__spice,elmarco/spice,alon/spice-server,mathslinux/spice,ya-mouse/spice,fgouget/spice,fgouget/spice,alon/spice-server,mathslinux/spice,mathslinux/spice,SPICE/spice,elmarco/spice,fgouget/spice,SPICE/spice,dezelin/spice,alon/spice-server,ya-mouse/spice,fgouget/spice,SPICE/spice,freedesktop-unofficial-mirror/spice__spice