Hyperlinks inserted when printing Thinklab pages

When I try to print out Thinklab pages, URLs get inserted after hyperlinks and result in an unaesthetic typesetting.

For example, the title of the composition window becomes:

New discussion in project: Thinklab Meta (/p/meta)

I assume this is due to a default bootstrap behavior, and I find it highly undesirable.

Fixed. Don't know why Bootstrap is doing that. Apparently they are removing that "feature" in version 4.