I am sorry Károly but I cannot reproduce this problem.
I checked the 3.5 hu.zip package downloaded from https://download.moodle.org/langpack/3.5/ and the file hu/admin.php does not have that typo.
As per the timeline for that string, that typo has been corrected since November 2013. Also in the backup repository of language packages it seems the string has always had the right spelling "kezdőoldalát" on the 3.5 branch.
It is a mystery to me how you could get that typo in a downloaded package.