Use more detailed error message if constructor fails

[mm-david]

Currently, if socket construction fails, the exception uses the message in $!. Because this error message comes from the last system call, it has less information that the specific message in $IO::Socket::errstr.

I recommend changing to use $IO::Socket::errstr to populate the exception if the socket cannot be created.

From the docs of IO::Socket::IP:

If the constructor fails, it will set $IO::Socket::errstr and $@ to an appropriate error message; this may be from $! or it may be some other string.

As an example, if the domain name of a WHOIS server cannot be resolved (e.g. whois.tonic.to), the message in $! is Invalid argument, whereas $IO::Socket::errstr is Name or service not known. The latter indicates a DNS error, whereas the former is difficult to understand.

[mm-david]

@nalobin would it be possible to make a new release for CPAN with this change? I know it's quite minor, but it would be much appreciated.

[nalobin]

Hello. Just uploaded Net-Whois-Raw-2.99039.tar.gz to CPAN