Fix input connect state check in _set_field_value

[Jedrzej Nowak]

Let's say my resource have Hash input named "a", with possible subvalues of "b" and "c" (a: {b:int, c:int})

When I will first set a value of "b" and then I will connect "c" with other resource everything is fine, but doing this in reverse, will raise Exception that a:c is connected with resource {r_name}:{input_name}.

This happens because _set_field_value doesn't check currently for complex types.