Possible fix for sharing a direct link #8180

More info see https://github.com/owncloud/core/issues/8180#issuecomment-51488885

How to build a test url
- Share an image
- you get an url like
``` https://xxx.xxxx.com/public.php?service=files&t=c6b8bb0f7d87fb4f4635bf47f0ce8c29 ```
copy the t value -> ```c6b8bb0f7d87fb4f4635bf47f0ce8c29 ```
And then go to
http://domain.com/public/c6b8bb0f7d87fb4f4635bf47f0ce8c29

Expected behaviour:
See the image full size.

Actual behaviour:
Redirect to files app