Add Stamps.com Stainless Steel 35 lb. Digital Scale

Thanks to jt70471 who reported this device on Github as issue #10

50-usb-scale.rules

@@ -1,6 +1,7 @@
 SUBSYSTEM=="usb", ATTR{idVendor}=="1446", ATTR{idProduct}=="6a73", MODE="0776"
 SUBSYSTEM=="usb", ATTR{idVendor}=="7b7c", ATTR{idProduct}=="0100", MODE="0776"
 SUBSYSTEM=="usb", ATTR{idVendor}=="2474", ATTR{idProduct}=="0550", MODE="0776"
+SUBSYSTEM=="usb", ATTR{idVendor}=="2474", ATTR{idProduct}=="3550", MODE="0776"
 SUBSYSTEM=="usb", ATTR{idVendor}=="0eb8", ATTR{idProduct}=="f000", MODE="0776"
 SUBSYSTEM=="usb", ATTR{idVendor}=="6096", ATTR{idProduct}=="0158", MODE="0776"
 SUBSYSTEM=="usb", ATTR{idVendor}=="0b67", ATTR{idProduct}=="555e", MODE="0776"

scales.h

@@ -30,6 +30,8 @@ uint16_t scales[NSCALES][2] = {\
     {0x7b7c, 0x0100},
     // Stamps.com Stainless Steel 5 lb. Digital Scale
     {0x2474, 0x0550},
+    // Stamps.com Stainless Steel 35 lb. Digital Scale
+    {0x2474, 0x3550},
     // Mettler Toledo
     {0x0eb8, 0xf000},
     // SANFORD Dymo 10 lb USB Postal Scale