dispatcher/ensure-and-redispatch.py: give the better handler a valid filter
dispatcher/ensure-and-redispatch.py: give the better handler a valid filter

The channel's immutable properties contain Interfaces, an 'as', which isn't
valid in a filter.

freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control,freedesktop-unofficial-mirror/telepathy__telepathy-mission-control