Yes, it has been removed for security reasons.
In last beta, we have added an environment variable to enable Javascript hyperlink back.
http://beta.plantuml.net/plantuml.jar
You have to set PLANTUML_JAVASCRIPT_UNSECURE to true :
set PLANTUML_JAVASCRIPT_UNSECURE=true
or
setenv PLANTUML_JAVASCRIPT_UNSECURE true
or
java -DPLANTUML_JAVASCRIPT_UNSECURE=true -jar /path/to/plantuml.jar ...
Tell us if it's not working for you!