Add enableProxyingHttpRequest description to Azure Functions host.json (SchemaStore#4881)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: satvu

src/schemas/json/host.json

@@ -1066,6 +1066,11 @@
               "description": "Forward HttpTrigger request to the custom handler",
               "type": "boolean",
               "default": false
+            },
+            "enableProxyingHttpRequest": {
+              "description": "Proxy HttpTrigger request to the custom handler",
+              "type": "boolean",
+              "default": false
             }
           },
           "additionalProperties": false