Fixed validation for Request parameter that is an array without default value

If Request parameter is an array without default value and parameter is not set - then an error should be thrown that "parameter value is not an array".

Steps to reproduce:
* Create a Request parameter with the following config
```
@RequestParam(name="clients", array=true)
```
* In a post request do not send this parameter at all

Actual result (before the fix):
* 'clients' parameter is set to an empty array 

Expected result (with the fix):
* Error "Request parameter value of 'clients' is not an array"

If empty array should be a default value if parameter is not set, then 'strict' should be set to false, example:

```
@RequestParam(name="clients", array=true, strict=false)
```