Revert "fake_slug hack"

This reverts commit 1763af155e.

app/src/frontend/building/data-container.tsx

@@ -248,7 +248,7 @@ const withCopyEdit: (wc: React.ComponentType<CategoryViewProps>) => DataContaine
             }
             
             const edits = (slug == 'current_landuse_group') ?
-             {['fake_slug']: value} : 
+             {['date_year']: value} : 
              {[slug]: value}
 
             this.doSubmit(edits);

app/src/frontend/config/data-fields-config.ts

@@ -632,8 +632,7 @@ export const dataFields = { /* eslint-disable @typescript-eslint/camelcase */
                 year_demolished: { min: 1993, max: 1994 },
                 lifespan: "2-5", overlap_present: "50%", links: ["", ""]}
         ]
-    },
-    fake_slug: {}
+    }
 };
 
 export const allFieldsConfig = {...dataFields, ...buildingUserFields};