UI: Fix overlapping click event handler (#614)
UI: Fix overlapping click event handler (#614)

The click event handler for links in the card display are overlapping:
The general event for opening the link in a new window matches on user
mentions, too. But user mentions cannot be opened in a new window.
Serubin/wekan,johnleeming/wekan,pro-to-tip/wekan,nztqa/wekan,oliver4u/WEKAN_runpartner,oliver4u/sap-wekan,johnleeming/wekan,wekan/wekan,oliver4u/sap-wekan,jtickle/wekan,ahmadassaf/libreboard,GhassenRjab/wekan,mario-orlicky/wekan,ahmadassaf/libreboard,jtickle/wekan,nztqa/wekan,johnleeming/wekan,nztqa/wekan,oliver4u/sap-wekan,GhassenRjab/wekan,jtickle/wekan,GhassenRjab/wekan,FSFTN/Wekan,Serubin/wekan,ddanssaert/wekan,johnleeming/wekan,wekan/wekan,ahmadassaf/libreboard,libreboard/libreboard,mario-orlicky/wekan,wekan/wekan,mario-orlicky/wekan,oliver4u/WEKAN_runpartner,wekan/wekan,ddanssaert/wekan,FSFTN/Wekan,pro-to-tip/wekan,ddanssaert/wekan,wekan/wekan,Serubin/wekan,libreboard/libreboard,oliver4u/WEKAN_runpartner