pin 3rd party dependency version and revert a config file change (#553)

* revert change

* pin dependency

Author: Brian969

reference-artifacts/config.example.json

@@ -1789,7 +1789,7 @@
             }
           }
         ],
-        "xxfirewall-manager": {
+        "firewall-manager": {
           "name": "FirewallMgr",
           "image-id": "ami-06fa2a9e6f8fae9f2",
           "instance-sizes": "c5.large",

src/lib/cdk-constructs/package.json

@@ -60,7 +60,7 @@
     "@aws-accelerator/custom-resource-security-hub-send-invites": "workspace:^0.0.1",
     "@aws-accelerator/custom-resource-r53-dns-endpoint-ips": "workspace:^0.0.1",
     "hash-sum": "^2.0.0",
-    "ip-num": "^1.2.2",
+    "ip-num": "1.2.2",
     "pascal-case": "^3.1.1",
     "tempy": "0.5.0"
   },