Issue search in wiki will not link if there are special characters (umlauts, etc) (BB-15544)

If you try to link issues within the wiki using Creole, for example:

<<issues milestone=2.0.0&status=open&status=new&status=on+hold>>

The issues will list, but there will be issues that are not linked if there are any special extended latin characters (umlauts, swedish Ø, etc)