False positive problem "not allowed to use stages more than once"

[guilim]

The plugin marks any stages directive as a problem if repeated multiple times in the Jenkinsfile.

However, it is a valid syntax when used:

• inside sequential stages (see the example 24 in the official doc). So one more level of stages under a stage directive is valid.
• inside matrix blocks (see the example 34 in the official doc). So one more level of stages under a matrix directive is valid.

[sgwozdz]

That will be hard to fix, for now I will disable this.