Muc: correctly parse the 'composing' chat state.
Muc: correctly parse the 'composing' chat state.

In 6b6f09d97f91de66c11a4b6a7e28222e8dc911f6 I replaced a lookup table
for parsing these with GEnum. What I (and the reviewer) didn't notice is
that the WockyMucMsgState enum doesn't actually correspond to the names
used in XEP-0085! Since 'typing' isn't a thing in XMPP, the 'composing'
state was misparsed.

freedesktop-unofficial-mirror/wocky,noonien-d/wocky,noonien-d/wocky,noonien-d/wocky,freedesktop-unofficial-mirror/wocky,freedesktop-unofficial-mirror/wocky