Migrate GetDeletedByName from ChannelStore to return error interface (#14709)

Automatic Merge

app/slackimport.go

@@ -536,7 +536,7 @@ func (a *App) SlackAddChannels(teamId string, slackchannels []SlackChannel, post
 		if mChannel, err = a.Srv().Store.Channel().GetByName(teamId, sChannel.Name, true); err == nil {
 			// The channel already exists as an active channel. Merge with the existing one.
 			importerLog.WriteString(utils.T("api.slackimport.slack_add_channels.merge", map[string]interface{}{"DisplayName": newChannel.DisplayName}))
-		} else if _, err := a.Srv().Store.Channel().GetDeletedByName(teamId, sChannel.Name); err == nil {
+		} else if _, nErr := a.Srv().Store.Channel().GetDeletedByName(teamId, sChannel.Name); nErr == nil {
 			// The channel already exists but has been deleted. Generate a random string for the handle instead.
 			newChannel.Name = model.NewId()
 			newChannel = SlackSanitiseChannelProperties(newChannel)