Fix display of page references when language is not specified

Fix display of page references when language is not specified

Using translateIfPossible with null language does not make sense (and
gives an error on console).

Using translateIfPossible there actually does not make sense at all: it
is only for string from layout files that may already be translated.

We use the GUI language when no language has been specified (this is
different and probably safer than what is done in master).

A consequence of the commit is that "elsewhere" will be in the po
files and now really translatable ;)

(cherry picked from commit 6f6d9b631d110fb71fcd99351b4f40d58451700a)