channeldb: refresh channel state within RefreshShortChanID

Refresh channel memory state whenever the short channel id is refreshed.
This is to make the in-memory channel consistent with the disk data.

Fixes #3765.

channeldb/channel_test.go

@@ -939,8 +939,8 @@ func TestFetchWaitingCloseChannels(t *testing.T) {
 }
 
 // TestRefreshShortChanID asserts that RefreshShortChanID updates the in-memory
-// short channel ID of another OpenChannel to reflect a preceding call to
-// MarkOpen on a different OpenChannel.
+// state of another OpenChannel to reflect a preceding call to MarkOpen on a
+// different OpenChannel.
 func TestRefreshShortChanID(t *testing.T) {
 	t.Parallel()
 
@@ -1038,4 +1038,10 @@ func TestRefreshShortChanID(t *testing.T) {
 			"got %v", chanOpenLoc,
 			pendingChannel.Packager.(*ChannelPackager).source)
 	}
+
+	// Check to ensure that this channel is no longer pending and this field
+	// is up to date.
+	if pendingChannel.IsPending {
+		t.Fatalf("channel pending state wasn't updated: want false got true")
+	}
 }