cxf - server transport isn't up properly

Fuse 7.12 CXF integrations tests are failing on SB due to:

WARN  ServletController:182 - Can't find the request for http://localhost:8080/services/rest-async/greeting-service's Observer

In order to reproduce the issue:

• clone https://gitlab.cee.redhat.com/jboss-fuse-qe/jbossqe-camel-it
• Run mvn clean install -am -amd -pl :async-feature-test -Pspring-boot -Dversion.redhat.fuse=7.12.0.fuse-7_12_0-00004-redhat-00001