THRIFT-2454: c_glib: There is no gethostbyname_r() in some OS

Patch: Jin-wook Jeong
diff --git a/configure.ac b/configure.ac
index 483c283..f4d1869 100755
--- a/configure.ac
+++ b/configure.ac
@@ -530,6 +530,7 @@
 AC_CHECK_FUNCS([bzero])
 AC_CHECK_FUNCS([ftruncate])
 AC_CHECK_FUNCS([gethostbyname])
+AC_CHECK_FUNCS([gethostbyname_r])
 AC_CHECK_FUNCS([gettimeofday])
 AC_CHECK_FUNCS([memmove])
 AC_CHECK_FUNCS([memset])