Author: Dani Palou
MDL-51935 wiki: Add missing strings in wiki
http://git.moodle.org/gw?p=moodle.git;a=commit;h=45e37067f61afe5c356cffeb40ffa512852308dd
http://github.com/moodle/moodle/commit/45e37067f61afe5c356cffeb40ffa512852308dd
+ 2.9 en [cannotcomparenewerversion,mod_wiki]
+ 2.9 en [incorrectpageid,mod_wiki]
+ 2.9 en [incorrectsubwikiid,mod_wiki]
+ 2.9 en [incorrectwikiid,mod_wiki]