"keep arrary indentation' breaks when 3-space indents, process with 4-space setting

[bitwiseman]

Related to #333

//---- js_beautify input -------
function foo() {
   return [
      {
         one: 'x',
         two: [
            {
               id: 'a',
               name: 'apple'
            }, {
               id: 'b',
               name: 'banana'
            }
         ]
      }
   ];
}
//---- js_beautify expected ----
function foo() {
   return [
      {
         one: 'x',
         two: [
            {
               id: 'a',
               name: 'apple'
            }, {
               id: 'b',
               name: 'banana'
            }
         ]
      }
   ];
}
//---- js_beautify output ------
function foo() {
    return [
        {
            one: 'x',
            two: [
                {
                    id: 'a',
                    name: 'apple'
            }, {
                    id: 'b',
                    name: 'banana'
            }
         ]
      }
   ];
}