rm warning in sjcl

Fixes sjcl warning on browsers by implementing the fix suggested on:
https://github.com/bitwiseshiftleft/sjcl/issues/142

Changing line 416 of core/random.js

from
```
   var or = "";
```
to
```
    var or = 0;
```

This fix is only implemented on the bundler version of sjcl. Rebuilding the bundle with reintroduce the bug.

Fixes https://github.com/bitpay/copay/issues/1582