Merge branch '3.1.x' into 3.2.x

* 3.1.x:
  [ticket/14241] Log fatal captcha error to error log
  [ticket/14241] Prevent empty q&a as a result of improper settings

phpBB/language/en/acp/common.php

@@ -606,6 +606,7 @@ $lang = array_merge($lang, array(
 
 	'LOG_ERROR_JABBER'		=> '<strong>Jabber error</strong><br />» %s',
 	'LOG_ERROR_EMAIL'		=> '<strong>Email error</strong><br />» %s',
+	'LOG_ERROR_CAPTCHA'		=> '<strong>CAPTCHA error</strong><br />» %s',
 
 	'LOG_FORUM_ADD'							=> '<strong>Created new forum</strong><br />» %s',
 	'LOG_FORUM_COPIED_PERMISSIONS'			=> '<strong>Copied forum permissions</strong> from %1$s<br />» %2$s',

phpBB/language/en/captcha_qa.php

@@ -40,6 +40,7 @@ $lang = array_merge($lang, array(
 	'CAPTCHA_QA'				=> 'Q&A',
 	'CONFIRM_QUESTION_EXPLAIN'	=> 'This question is a means of preventing automated form submissions by spambots.',
 	'CONFIRM_QUESTION_WRONG'	=> 'You have provided an invalid answer to the question.',
+	'CONFIRM_QUESTION_MISSING'	=> 'Questions for the captcha could not be retrieved. Please contact a board administrator.',
 
 	'QUESTION_ANSWERS'			=> 'Answers',
 	'ANSWERS_EXPLAIN'			=> 'Please enter valid answers to the question, one per line.',
@@ -60,5 +61,4 @@ $lang = array_merge($lang, array(
 
 	'QA_ERROR_MSG'				=> 'Please fill in all fields and enter at least one answer.',
 	'QA_LAST_QUESTION'			=> 'You cannot delete all questions while the plugin is active.',
-
 ));