src/common/dns_resolve.cc: reorder the includes

[wjwithagen]

• dns_resolv.h should only be include after all the std-includes are
  made. Otherwise it will result into undefined structs/variables on
  FreeBSD/Clang

Signed-off-by: Willem Jan Withagen wjw@digiware.nl

[cbodley]

can we try to fix dns_resolve.h instead, so we don't have to worry about other source files that include it? the header itself should include all of its dependencies

[wjwithagen]

@cbodley
That is a more invasive fix, but makes perfect sense.
Although the coding standard actually requires to first include the system include files
and only then the local project include files. (exceptions left aside)

[wjwithagen]

please retest this

[xiexingguo]

@wjwithagen
retest this please

shall work:-)

[wjwithagen]

@xiexingguo
I was wondering.... Thanx.