THRIFT-2887 Respect --with-openssl when building C++ support.
diff --git a/configure.ac b/configure.ac
index ce9191f..6d55f8a 100755
--- a/configure.ac
+++ b/configure.ac
@@ -137,6 +137,8 @@
     have_cpp="yes"
   fi
 
+  AX_CHECK_OPENSSL()
+
   AX_LIB_EVENT([1.0])
   have_libevent=$success