check whatever we can read from the channel
check whatever we can read from the channel

```
panic: interface conversion: interface {} is nil, not types.TMEventData

goroutine 7690 [running]:
github.com/tendermint/tendermint/consensus.waitForAndValidateBlock.func1(0xc427727620, 0x3)
        /go/src/github.com/tendermint/tendermint/consensus/reactor_test.go:292 +0x62b
created by github.com/tendermint/tendermint/consensus.timeoutWaitGroup
        /go/src/github.com/tendermint/tendermint/consensus/reactor_test.go:349 +0xa4
exit status 2
FAIL    github.com/tendermint/tendermint/consensus      38.614s

```

tendermint/tendermint,tendermint/tendermint,tendermint/tendermint,tendermint/tendermint