Build failure with GCC 10

[felixonmars]

In file included from /usr/include/string.h:495,
                 from /usr/include/libcork/core/net-addresses.h:14,
                 from /usr/include/libcork/core.h:24,
                 from netutils.c:25:
In function ‘strncpy’,
    inlined from ‘setinterface’ at netutils.c:88:5:
/usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 16 equals destination size [-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/string.h:495,
                 from /usr/include/libcork/core/net-addresses.h:14,
                 from /usr/include/libcork/core.h:24,
                 from netutils.c:25:
In function ‘strncpy’,
    inlined from ‘setinterface’ at netutils.c:88:5:
/usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 16 equals destination size [-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~