tuupola/jquery_lazyload — pull request #190 by Martin91 (2014-04-14 07:49:37+00:00)
Title: one more placeholder case for blank src attribute

In some templates, such as ERB for Rails, it will automatically generate a `` tag likes:
``` html

```
so the plugin will not work because the `if` in https://github.com/tuupola/jquery_lazyload/blob/master/jquery.lazyload.js#L92
``` js
if ($self.attr("src") === undefined || $self.attr("src") === false) {
```
will always be false, and the placeholder will not be shown.

I append a new case which considers a blank `src` attribute like `''`.