[202012][Security][CVE-2022-2309] Upgrade lxml from 4.6.5 to 4.9.1

Author: xumia

src/sonic-config-engine/setup.py

@@ -7,7 +7,7 @@
 dependencies = [
     'bitarray==1.5.3',
     'ipaddress==1.0.23',
-    'lxml==4.6.3',
+    'lxml==4.9.1',
     'netaddr==0.8.0',
     'pyyaml==5.4.1',
     'sonic-py-common',