Remove obsolete undertow dependency

First introduced in 724b2a2eec58208588426eb5b7088c988fd04a2d

Usages removed in 83bd0e7b054d12048cfd67b658e1a6ef212104f3 -
`src/main/groovy/com/ofg/mock/MicroserviceDependenciesRunner.groovy` that was using `org.jboss.resteasy.plugins.server.undertow.UndertowJaxrsServer`