Calculating len of img_obj's fs_file_ids rather than hardcoding as index 1

**Previously, to get profile_pic we were using :**
``` img_obj.fs_file_ids[1] ```

*Sometimes, this gives an error of - ```list index out of bound```*

**Now, to get profile_pic, I have replaced above with :**
```img_fs = img_obj.fs_file_ids[ len(img_obj.fs_file_ids) - 1 ]```

*This will handle all the list length related issues*