fixed bug with dc-dc polarity in CANbus4BTA

F0:F030,F042,F072/CANbus4BTA/kicad/stm32.kicad_prl

@@ -1,7 +1,7 @@
 {
   "board": {
-    "active_layer": 37,
-    "active_layer_preset": "Front Assembly View",
+    "active_layer": 0,
+    "active_layer_preset": "All Layers",
     "auto_track_width": false,
     "hidden_nets": [],
     "high_contrast_mode": 0,
@@ -62,7 +62,7 @@
       35,
       36
     ],
-    "visible_layers": "00290a0_00000000",
+    "visible_layers": "fffffff_ffffffff",
     "zone_display_mode": 0
   },
   "meta": {