GCC 14 newly by default treats as errors a number of situations which
before were only warnings.  For more information see
https://gcc.gnu.org/gcc-14/porting_to.html and meta bug #1220571.

Because of this, package libesmtp fails to compile.  This can be seen online
at:
https://build.opensuse.org/package/live_build_log/openSUSE:Factory:Staging:Gcc7/libesmtp/standard/x86_64

It can be reproduced locally with command: osc build --clean
--alternative-project home:rguenther:nextgcc

Notes from fedora-modernc project however suggest that "removing
autotools" is necessary:
https://gitlab.com/fweimer-rh/fedora-modernc/-/blob/main/pkg/l/libesmtp.md?ref_type=heads


The (first) error (that halts the build) is:

[   24s] ../smtp-api.c: In function ‘smtp_version’:
[   24s] ../smtp-api.c:1183:7: error: implicit declaration of function
‘strlcpy’; did you mean ‘strncpy’? [-Wimplicit-function-declaration]
[   24s]  1183 |   if (strlcpy (buf, v, len) > len)
[   24s]       |       ^~~~~~~
[   24s]       |       strncpy