multi: fix a-vs-an typos

lntest/node.go

@@ -602,7 +602,7 @@ func (hn *HarnessNode) lightningNetworkWatcher() {
 			// TODO(roasbeef): add update type also, checks for
 			// multiple of 2
 			if watchRequest.chanOpen {
-				// If this is a open request, then it can be
+				// If this is an open request, then it can be
 				// dispatched if the number of edges seen for
 				// the channel is at least two.
 				if numEdges := openChans[targetChan]; numEdges >= 2 {