Fix dictionary definition passed into the spec methods

[andsel]

Fix dictionary definition passed into the spec methods, to be compliant with JRuby 9.4

How to test

Same steps as logstash-plugins/logstash-filter-cidr#26 but adding

-J-Djruby.regexp.interruptible=true

to the JRUBY_OPTSenvironment variable

[roaksoax]

LGTM, however I only see the changes in the array, not JRUBY_OPTS?

So approving the array changes here.

If you need to add the JRUBY_OPTS< please put a follow up branch.

[andsel]

JRUBY_OPTS it' need only when using the plain JRuby installed on the system. When tested on CI it uses the JRuby provided by Logstash which is already configured with this setting.