changes: Add file for MR 839

Signed-off-by: David Goulet <dgoulet@torproject.org>

changes/ticket40248

+  o Minor bugfix (client DNS):
+    - Handle empty DNS reply without sending back an error and instead send back
+      NOERROR (RFC1035 error code 0x0). Fixes bug 40248; bugfix on
+      0.3.5.1-alpha.