Single PHP-style array values now parse into array.

The following query string example:
http://test.com/test.php?myarray[]=test
gets converted to
http://test.com/test.php?myarray=test

which means that PHP then receives a single value in $_GET instead of an array containing a single value.

This works fine with multiple values as follows:
http://test.com/test.php?myarray[]=test&myarray[]=test2

If you make a request for the original URL (http://test.com/test.php?myarray[]=test) from a browser, PHP will receive an array with a single element, which is the behaviour I would expect.

I'm not sure whether or not this is a bug or if this is intended behaviour. However, this PR "fixes" the problem.