lablgtk-extras.1.6 and odoc-depgraph.1.0 are 404

CC @zoggy 
```
  - [lablgtk-extras.1.6] https://github.com/zoggy/lablgtk-extras/archive/release-1.6.tar.gz
    (code 404 while downloading
    https://github.com/zoggy/lablgtk-extras/archive/release-1.6.tar.gz)
  - [odoc-depgraph.1.0] https://github.com/zoggy/odoc_depgraph/archive/v1.0.tar.gz (code 404
    while downloading https://github.com/zoggy/odoc_depgraph/archive/v1.0.tar.gz)
```