Added OS detection to getpwuid

Since getpwuid is not implemented on Windows

cgi-bin/hello_host.cgi

@@ -21,7 +21,7 @@ my $myip = $ENV{'SERVER_ADDR'};
 my $myport = $ENV{'SERVER_PORT'};
 my $myhostname = hostname;
 my $mylocaltime = &mygetstrtime;
-my $username = getpwuid( $< );
+my $username = ( $^O eq "MSWin32" ? '' : getpwuid( $< ));
 
 print "Client:\n";
 print "  $ip:$port\n";