[PATCH] IpAdress truncates printed port that exceeds 9999

Fixed IpAddress port printing for ports higher than 9999:
snprintf includes zero-terminator in its size limit, so 7
rather than 6 bytes are needed to snprintf a colon followed
by 5 port digits.

Whether the bug has any runtime effects in the current code,
I do not know, but I did waste a few hours following
misleading debugging output.

Alex.