fix ArrayWriter.skip()

src/add/class.js

@@ -11,7 +11,7 @@ self.ArrayWriter = class ArrayWriter {
     }
 
     skip(len) {
-        this.pos += len;
+        this.writeBytes(new Array(len).fill(0), len);
         return this.pos;
     }
 

src/mode/sla/export.js

@@ -122,7 +122,6 @@
             }
             let preview1 = [];
             let pdata = SLA.previewLarge.data;
-console.log({pdata});
             for (let x=0; x<290; x++) {
                 for (let y=0; y<290; y++) {
                     let p = (x * 290 + y) * 4;