Parameters without descriptions do not fail the validation

[reckart]

For some reason, parameters that do not have descriptions pass the validation in the Maven plugin, but when trying to publish them to the OMTD registry, the validation fails with

System error making this component public (Server responded: cvc-complex-type.2.4.a: Invalid content was found starting with element 'ms:parameterType'. One of '{"http://www.meta-share.org/OMTD-SHARE_XMLSchema":parameterDescription}' is expected.)