Comment 0 for bug 1646156

As seen at
    http://reports.vapour.ws/releases/issue/583ee3dd749a564faa2a113c

panic: send on closed channel

goroutine 23761 [running]:
panic(0x115dc800, 0xc820940990)
 /usr/lib/go-1.6/src/runtime/panic.go:481 +0x3a0
github.com/juju/juju/state/watcher.(*Watcher).flush(0xc821be4e10)
 /home/ubuntu/juju-core_2.1-beta2/src/github.com/juju/juju/state/watcher/watcher.go:260 +0x49c
github.com/juju/juju/state/watcher.(*Watcher).loop(0xc821be4e10, 0x0, 0x0)
 /home/ubuntu/juju-core_2.1-beta2/src/github.com/juju/juju/state/watcher/watcher.go:238 +0x118
github.com/juju/juju/state/watcher.New.func1(0xc821be4e10)
 /home/ubuntu/juju-core_2.1-beta2/src/github.com/juju/juju/state/watcher/watcher.go:116 +0x38
created by github.com/juju/juju/state/watcher.New
 /home/ubuntu/juju-core_2.1-beta2/src/github.com/juju/juju/state/watcher/watcher.go:126 +0x174
FAIL github.com/juju/juju/cmd/jujud/agent 108.634s
? github.com/juju/juju/cmd/jujud/agent/agenttest [no test files]