Resolve "Change definition of "maxsize""

Closes #2130 (closed).

Quite the interesting bug. log4cplus uses std::atoi to translate the string to integer. So even though they assign it to a long, it overflows on int32 because of the std::atoi. Here is a reference of that behavior: is returned as a value of type int. So we use the KB or the MB in case of eventual overflowing and that's it. Since the out of range value from the Kea user's perspective is now lightyears away, I think there's no reason for the warning, agree?