[Evolution-hackers] Building with --enable-ipv6=no uses gai_strerror()

[Albert Chin <evolution-hackers mlists thewrittenword com>]

Seems a replacement for gai_strerror() isn't available when building
with --enable-ipv6=no. This leads to an unresolved issue on Solaris
2.6, 7 building evolution-data-server-1.2.3:
  Undefined                       first referenced
   symbol                             in file
  gai_strerror                        ./.libs/libcamel-1.2.so
  ld: fatal: Symbol referencing errors. No output written to .libs/camel-index-control-1.2

-- 
albert chin (china thewrittenword com)