camel-net-utils: Replace deprecated unicode function
uidna_IDNToASCII is deprecated, the whole function can now be replaced by the use of uidna_nameToASCII_UTF8.
/eds/src/camel/camel-net-utils.c: In function ‘camel_host_idna_to_ascii’:
/eds/src/camel/camel-net-utils.c:838:25: warning: ‘uidna_IDNToASCII_73’ is deprecated [-Wdeprecated-declarations]
838 | nconverted = uidna_IDNToASCII (uhost, uhost_len, buffer, buffer_len, UIDNA_ALLOW_UNASSIGNED, 0, &uerror);
| ^~~~~~~~~~
In file included from /usr/include/unicode/platform.h:25,
from /usr/include/unicode/ptypes.h:52,
from /usr/include/unicode/umachine.h:46,
from /usr/include/unicode/utypes.h:38,
from /usr/include/unicode/uidna.h:22,
from /eds/src/camel/camel-net-utils.c:28:
/usr/include/unicode/uidna.h:679:1: note: declared here
679 | uidna_IDNToASCII( const UChar* src, int32_t srcLength,
| ^~~~~~~~~~~~~~~~