Bug 7738: "Display more constraints' in subfield configuraiton is not properly transl...

Bug 7738: "Display more constraints' in subfield configuraiton is not properly translatable

The Javascript toggling the link description was checking for the english
link text. This would not work for translated templates.

Tested: Apply patch, then translate update and translate install.
Text changes as appropriate (with manually inserted translation in .po file)

Signed-off-by: mveron <veron@veron.ch>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>