inital preview data is not appended because there is no assignment

[koxu1996]

Today I usedfilesortedevent and I got stack which was array of undefined. I debugged code and figured out these lines are the problem: https://github.com/kartik-v/bootstrap-fileinput/blob/master/js/fileinput.js#L1636-L1638
concat() does not change existing arrays, so new data are initialPreview, initialPreviewThumbTags, initialPreviewConfig are unmodified after upload. Simple fix and I am getting correct stack:

self.initialPreview = self.initialPreview.concat(content);
self.initialPreviewThumbTags = self.initialPreviewThumbTags.concat(tags);
self.initialPreviewConfig = self.initialPreviewConfig.concat(config);

Am I right?