[SUREFIRE-1874] useManifestOnlyJar not used by default for failsafe

**[Gabriel Landais](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=glandais-sparklane)** opened **[SUREFIRE-1874](https://issues.apache.org/jira/browse/SUREFIRE-1874?redirect=false)** and commented

In IntegrationTestMojo(AbstractSurefireMojo).createForkConfiguration, JAR is ready and as useModulePath is set to true by default, "modular classpath" is used.

useModulePath has to be set to false for getting the "manifest only jar" working.

useManifestOnlyJar or useModulePath should be set to false for not confusing users.

---

**Affects:** 3.0.0-M5

Start at IntegrationTestMojo(AbstractSurefireMojo).createForkConfiguration and trace how useManifestOnlyJar and useModulePath determine the classpath for Failsafe. Compare the defaults and existing behavior, then determine which setting should change so the options are not confusing; done means the intended default works and the behavior is covered by a regression test.

Written by the indexing model from the issue text.