Empty Parameter replaced with Parameter literal

When empty Job Parameter passed though jenkins to invoke gradle script, it do not evaluate to empty but takes parameter name in gradle script.

Steps to reproduce: 

1. Passing empty parameter to jenkins job

2. Executing gradle script using Job parameter 

3. Job execution takes job parameter to be literal, while expected empty

Might be a regression from : https://issues.jenkins-ci.org/browse/JENKINS-42573