Fix double unit in batteries datasheet.

datasheets/batteries.json

@@ -4,7 +4,7 @@
         "item description":"Power Functions Rechargeable Battery Box",
         "category":"battery",
         "price [Euro]":55,
-        "mass [g] [g]":83.94,
+        "mass [g]":83.94,
         "delivery time [days]":8,
         "data source":"https:\/\/www.bricklink.com\/v2\/catalog\/catalogitem.page?S=8878-1#T=S&O={%22iconly%22:0}",
         "output voltage [V]":7.4,
@@ -15,7 +15,7 @@
         "item description":"Power Functions Battery Box",
         "category":"battery",
         "price [Euro]":12,
-        "mass [g] [g]":179.4,
+        "mass [g]":179.4,
         "delivery time [days]":3,
         "data source":"https:\/\/www.bricklink.com\/v2\/catalog\/catalogitem.page?S=8881-1#T=S&O={%22iconly%22:0}",
         "output voltage [V]":9.0,
@@ -26,7 +26,7 @@
         "item description":"Lego AAA Battery Box",
         "category":"battery",
         "price [Euro]":30,
-        "mass [g] [g]":97.24,
+        "mass [g]":97.24,
         "delivery time [days]":6,
         "data source":"https:\/\/www.brickowl.de\/catalog\/lego-aaa-battery-box-set-88000",
         "output voltage [V]":9.0,
@@ -37,7 +37,7 @@
         "item description":"Electric 9V Battery Box",
         "category":"battery",
         "price [Euro]":2,
-        "mass [g] [g]":172.7,
+        "mass [g]":172.7,
         "delivery time [days]":3,
         "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,
@@ -48,7 +48,7 @@
         "item description":"LEGO Power Functions Battery Box ",
         "category":"battery",
         "price [Euro]":18,
-        "mass [g] [g]":165.3,
+        "mass [g]":165.3,
         "delivery time [days]":3,
         "data source":"https:\/\/www.brickowl.de\/catalog\/lego-power-functions-battery-box-with-beam-connectors-with-on-off-sticker-59510",
         "output voltage [V]":9.0,
@@ -59,7 +59,7 @@
         "item description":"Electric 9V Power Functions Battery Box (Rechargeable)",
         "category":"battery",
         "price [Euro]":120,
-        "mass [g] [g]":82.0,
+        "mass [g]":82.0,
         "delivery time [days]":8,
         "data source":"https:\/\/www.bricklink.com\/v2\/catalog\/catalogitem.page?P=84599&name=Electric%209V%20Battery%20Box%20Power%20Functions%20(Rechargeable)%20with%20Dark%20Bluish%20Gray%20Bottom&category=%5BElectric,%20Battery%20Box%5D#T=S&O={%22iconly%22:0}",
         "output voltage [V]":9.0,