The issue is caused by oversimplified parameters parsing implementation in this class: https://github.com/jenkinsci/groovy-plugin/blob/master/src/main/java/hudson/plugins/groovy/Groovy.java
I would suggest to switch to org.apache.commons.exec.CommandLine.parse(..) method from Apache commons-exec.
Not ideal, I know, but probably the best possible option if parsing command-line is inevitable.
Is anyone interested in the patch? It would be very straightforward.