Fix syntax in .json

datasheets/batteries.json

@@ -42,5 +42,5 @@
         "data source":"https://www.bricklink.com/v2/catalog/catalogitem.page?P=2847c01&name=Electric%209V%20Battery%20Box%204%20x%2014%20x%204%20with%20Red%20Buttons%20and%20Contact%20Plate%20with%20Dark%20Gray%20Base%20(2846%20/%202847c00)&category=%5BElectric,%20Battery%20Box%5D#T=S&O={%22iconly%22:0}",
         "output voltage [V]":9.0,
         "dimensions [cm]":"11,2 x 3,2 x 3,2"
-    },
+    }
 }