At the moment the plugin requires the Jira `site` mandatory parameter, e.g.:

`jiraSendBuildInfo site: example.atlassian.net`

The site parameter is a reference to the Jira Cloud Site config in the Jenkins Global configuration.

In order to simplify the configuration, the idea is to make the site parameter optional.

`jiraSendBuildInfo`

If not provided, we would fetch all the Jira Site Configs defined in the Global config. If only one Jira Site Config is defined, we would use the site. Otherwise, if multiple sites are defined we would log a warning and ask the use to fix the Jenkinsfile, i.e. provide the site parameter.