Cannot pass null as param to Client.invoke

[ivantv]

We are not able to pass null as param to invoke. A small fix is needed in javaJmx.js:

  function jsParams2JavaParams(params, signature) {
    var javaParams = [];
    signature.forEach(function(className) {
      var value = params.shift();
      if (value!= null && typeof value.getClass !== "function") { // Fix

[zuazo]

@ivantv thanks for reporting!

¿Could you make a PR for this and include at least one test for your use case?