Merge pull request #5539 from grpc/makdharma-comment

Update reconnect_interop_server.cc
diff --git a/test/cpp/interop/reconnect_interop_client.cc b/test/cpp/interop/reconnect_interop_client.cc
index 1f6b352..3ad733e 100644
--- a/test/cpp/interop/reconnect_interop_client.cc
+++ b/test/cpp/interop/reconnect_interop_client.cc
@@ -30,7 +30,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
-
+// Test description at doc/connection-backoff-interop-test-description.md
 #include <memory>
 #include <sstream>