fix pico pcb clearance

rev2/3d-models/top-dampener.scad

@@ -191,10 +191,10 @@ module case(){
                 +$usbOffsetFromPcb - $picoPcbClearanceFromBase
             ])
                 // Make clearance downwards for the pico board
-                #cube([
+                cube([
                     $picoWidth,
                     $picoLength, 
-                    $picoPcbClearanceFromBase
+                    $picoPcbClearanceFromBase + $clearance
                 ]);
         }
     }