Correctly calculate offset in writeVString, fixes #20

Author: dcodeIO

dist/ByteBufferAB.js

@@ -1756,8 +1756,8 @@
             }
             var start = offset,
                 k, l;
-            l = ByteBuffer.calculateVarint32(k);
             k = utf8_calc_string(str);
+            l = ByteBuffer.calculateVarint32(k);
             offset += l+k;
             var capacity15 = this.buffer.byteLength;
             if (offset > capacity15)

dist/ByteBufferAB.min.js

@@ -28,8 +28,8 @@ ByteBuffer.prototype.writeVString = function(str, offset) {
     buffer.copy(this.buffer, offset);
     offset += buffer.length;
     //? } else {
-    l = ByteBuffer.calculateVarint32(k);
     k = utf8_calc_string(str);
+    l = ByteBuffer.calculateVarint32(k);
     //? ENSURE_CAPACITY('l+k');
     offset += this.writeVarint32(k, offset);
     k = str.length;