[FIX] Correction of the setMTSParam method in the case of a list variable.

[othomas-dev]

I have made a correction to the setMTSParam method (MTSScript.groovy) to avoid overwriting the list on each iteration (see: issue #64).
This allows to set a 'list' variable into MTS ParameterPool.

    /**
     * set a variable into MTS ParameterPool
     *
     */
    protected void setMTSParam(String name, Object value) {
        try {
            //println "MTSBinder.setMTSParam($name)"
            Parameter groovyParameter = new Parameter();
            if (value != null && value instanceof List) {
                value.each{groovyParameter.add(parseParameter(it))}
            } else {
                groovyParameter= parseParameter(value);
            }
            binding.runner.getParameterPool().set(ParameterPool.bracket(name), groovyParameter);
        } catch (ParameterException e) {
            e;
            e.printStackTrace();
        }
    }

[othomas-dev]

Is there anyone that could take a look at this PR? @egwepas ?
Thanks a lot,