[Console] fixed shell bug (#7068)

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7068
| License       | MIT
| Doc PR        | 

When "<command> --help" is called first, the mergeApplicationDefinition merge only the options for <command> and set applicationDefinitionMerged = true.
The second time "<command>" is called, the arguments is not merged because the applicationDefinitionMerged has been already set.