call qsprintf() without warnings
After T13217 import_repository_symbols.php was showing a lot of warnings, using %LQ fixes that.
I'm aware, that there are changes planned to the whole managing the symbols complex but until then less warnings are nice.
Test Plan: No more warnings when updating symbols
Reviewers: Blessed Reviewers, epriestley
Reviewed By: Blessed Reviewers, epriestley
Subscribers: Korvin, epriestley
Differential Revision: https://secure.phabricator.com/D19962