crash using slack when clearing away

[Peter4825]

similar to #143 but with clearly different stacktrace: just idling on slack gave me the following error, no idea what I did to cause it (altough I guess it has to do with my auto-away I guess):

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x71 pc=0x83c82d]

goroutine 142 [running]:
github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit.CmdAway(0x9c03e0, 0xc4200791e0, 0xc420178000, 0xc420232000, 0xc4200e3c28, 0x1)
/go/src/github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit/server_commands.go:39 +0x2d
github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit.commands.Run(0xc420163320, 0x9c03e0, 0xc4200791e0, 0xc420178000,
0xc420232000, 0xc4201bbd78, 0xc420066240)
/go/src/github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit/commands.go:51 +0x1d3
github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit.(*server).handle.func1(0xc4200791e0, 0xc420178000, 0xc420232000,
0xc42068e100)
/go/src/github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit/server.go:368 +0x7a
created by github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit.(*server).handle /go/src/github.com/42wim/matterircd/vendor/github.com/42wim/mm-go-irckit/server.go:367 +0x107

[Peter4825]

Seems I can reproduce this by setting myself away and then unsetting away...