#2 fix build with -Werror=format-security

[Dan Horak]

fix build with -Werror=format-security, see https://fedoraproject.org/wiki/Format-Security-FAQ for more information

[XavierBR]

I had to make minor modifications to make it work in my build script.

[Kevin Adler]

Thanks for the patch! I believe this has been merged in the latest release at https://github.com/tn5250/tn5250/releases/tag/v0.17.6