Update Entity.json

schema/Entity.json

@@ -186,7 +186,7 @@
       },
       "propertyNames": {
         "type": "string",
-        "pattern": "^(((\\d|[a-zA-Z]|_)+(:((\\d|[a-zA-Z]|_))+)?(#\\d+)?)$|^(@context)$"
+        "pattern": "^((\\d|[a-zA-Z]|_)+(:(\\d|[a-zA-Z]|_)+)?(#\\d+)?)$|^(@context)$"
       }
     },
     "Entity": {