MDL-29164 question import, missing lang string.

AMOS BEGIN
 CPY [noquestionsinfile,mod_quiz],[noquestionsinfile,question]
AMOS END

lang/en/question.php

@@ -217,6 +217,7 @@
 $string['nopermissionadd'] = 'You don\'t have permission to add questions here.';
 $string['nopermissionmove'] = 'You don\'t have permission to move questions from here. You must save the question in this category or save it as a new question.';
 $string['noprobs'] = 'No problems found in your question database.';
+$string['noquestionsinfile'] = 'There are no questions in the import file';
 $string['notenoughanswers'] = 'This type of question requires at least {$a} answers';
 $string['notenoughdatatoeditaquestion'] = 'Neither a question id, nor a category id and question type, was specified.';
 $string['notenoughdatatomovequestions'] = 'You need to provide the question ids of questions you want to move.';