Bug with latest GCC 9

[Martin Liška]

Hi.

As mentioned here:
https://bugzilla.opensuse.org/show_bug.cgi?id=1123136

there's a new issue with GCC 9, it's related to:
https://gcc.gnu.org/gcc-9/porting_to.html#complit

in:
/* Not const! Never return this as a result directly! */
#define SMTP_ADDRESS_LITERAL(localpart, domain) \
	&((struct smtp_address){ (localpart), (domain) })

Thanks,
Martin