"Link to this page" appears blank

[mdorf]

Steps to reproduce:

1. Go to an ontology classes page:
   https://bioportal.bioontology.org/ontologies/EPO?p=classes
2. Click on a term
3. Click on the icon to "Get the link to this page":
4. The textbox appears empty.
5. If it does NOT appear empty, click on several different terms and repeat the procedure above.

[mdorf]

This is still reproducible after merging the PR ontoportal#28:

[syphax-bouazzouni]

For information, this is the line that is responsible of putting the URL in that input https://github.com/ontoportal/ontoportal_web_ui/pull/28/files#diff-9ec3505b9293f850ab67eaa0d169c783a1b4ce3d221f2f049c90ce3e372b93ecR32
You can debug it to see what can be the reason.