fix: count nil vote as a signed block (#109)

Author: MattKetmo

pkg/watcher/block.go

@@ -253,7 +253,7 @@ func (w *BlockWatcher) computeValidatorStatus(block *types.Block) []ValidatorSta
 		for i, sig := range block.LastCommit.Signatures {
 			if val.Address == sig.ValidatorAddress.String() {
 				bonded = true
-				signed = (sig.BlockIDFlag == types.BlockIDFlagCommit)
+				signed = (sig.BlockIDFlag != types.BlockIDFlagAbsent)
 				rank = i + 1
 			}
 			if signed {

pkg/watcher/block_types.go

@@ -19,7 +19,7 @@ func NewBlockInfo(block *types.Block, validatorStatus []ValidatorStatus) *BlockI
 	// Compute total signed validators
 	signedValidators := 0
 	for _, sig := range block.LastCommit.Signatures {
-		if sig.BlockIDFlag == types.BlockIDFlagCommit {
+		if sig.BlockIDFlag != types.BlockIDFlagAbsent {
 			signedValidators++
 		}
 	}