MDL-41248 completion: fix non-translatable text.

There were two hard-coded strings. Thanks to Guido Hornig for the suggested fix.
Merge branch 'wip-MDL-44258-m25' of git://github.com/marinaglancy/moodle into MOODLE_25_STABLE
Merge branch 'MDL-41248_25' of git://github.com/timhunt/moodle into MOODLE_25_STABLE
MDL-44287 glossary: fixing warnings when importing as new module
MDL-44287 glossary: do not output before redirecting
MDL-44337 glossary: behat test for glossary categories