jetty:run-war <webApp> definition conflicts with <war>

The <war> element was aliased to <webApp> to maintain backwards compatibility with the old names, however, now that the jetty:run mojo uses <webApp> as the preferred name of the JettyWebAppContext object being configured, that causes a conflict.

The solution is to take out the alias to <webApp> for the jetty:run-war goal, and to just use the <war> element name instead.