chore: more tweaks to camera snapshot URLs

Author: MrYuion

src/app/overlays/item-modal.component.ts

@@ -270,7 +270,7 @@ export class ItemCreateUpdateModalComponent
                       { ...item_json, ...this.form.value },
                       this.item_type === 'user'
                           ? [undefined, null, '']
-                          : [undefined, null],
+                          : [undefined],
                   )
                 : { ...item_json, ...this.form.value }
         ) as Identity;

src/app/systems/systems.utilities.ts

@@ -49,7 +49,9 @@ export function generateSystemsFormFields(system?: PlaceSystem) {
         ]),
         camera_url: new FormControl(system.camera_url || '', [validateURL]),
         camera_snapshot_url: new FormControl(
-            system.camera_snapshot_url || system.camera_snapshot_urls[0] || '',
+            system.camera_snapshot_url ||
+                system.camera_snapshot_urls[0] ||
+                null,
         ),
         camera_snapshot_urls: new FormControl(
             system.camera_snapshot_urls