Fix SYJS-38 - Events stuck in 'sending' state
v1 used to clobber events after sending so `.status` would be `null`. v2 is
smarter and just clobbers the `.event` data so references to the local echo
event would reflect the new event. However, the `.status` in this case would
still have the old value (SENDING), so make sure to reset it after the 200 OK
from sending the event.
