Update fixture for django simple history (#285)

Author: mfosterw

democrasite/webiscite/fixtures/democrasite.json

@@ -23,7 +23,7 @@
       "bill": 1,
       "user": 1,
       "support": false,
-      "created": "2024-02-14T01:17:31.346Z"
+      "when": "2024-02-14T01:17:31.346Z"
     }
   },
   {
@@ -33,7 +33,7 @@
       "bill": 3,
       "user": 1,
       "support": true,
-      "created": "2024-02-14T01:26:18.533Z"
+      "when": "2024-02-14T01:26:18.533Z"
     }
   },
   {