Fix new warnings from GCC 7

Peter Eisentraut <peter_e@gmx.net>

Commit: de973f6e75e05c532d78d4ee98d55322ab166529
Author: Peter Eisentraut <peter_e@gmx.net>
Date: 2017-05-15T17:31:35Z
Releases: 9.2.22
Fix new warnings from GCC 7

This addresses the new warning types -Wformat-truncation
-Wformat-overflow that are part of -Wall, via -Wformat, in GCC 7.

Files