bump python 3.9 to latest patch in appveyor ci

Signed-off-by: oleg.hoefling <oleg.hoefling@gmail.com>

Author: hoefling

.appveyor.yml

@@ -9,9 +9,9 @@ environment:
   - python: 38
   - python: 38-x64
   - python: 39
-    python_version: 3.9.0
+    python_version: 3.9.13
   - python: 39-x64
-    python_version: 3.9.0
+    python_version: 3.9.13
 
 install:
   - ps: |