fix lang key

public/language/en_GB/error.json

@@ -67,7 +67,7 @@
 	"post-delete-duration-expired-days": "You are only allowed to delete posts for %1 day(s) after posting",
 	"post-delete-duration-expired-days-hours": "You are only allowed to delete posts for %1 day(s) %2 hour(s) after posting",
 
-	"cant-delete-topic-has-reply": "You can't delete your topic after it has %1 reply",
+	"cant-delete-topic-has-reply": "You can't delete your topic after it has a reply",
 	"cant-delete-topic-has-replies": "You can't delete your topic after it has %1 replies",
 
 	"content-too-short": "Please enter a longer post. Posts should contain at least %1 character(s).",

src/privileges/topics.js

@@ -208,8 +208,10 @@ module.exports = function(privileges) {
 
 			var preventTopicDeleteAfterReplies = parseInt(meta.config.preventTopicDeleteAfterReplies, 10) || 0;
 			if (preventTopicDeleteAfterReplies && (topicData.postcount - 1) >= preventTopicDeleteAfterReplies) {
-				var langKey = preventTopicDeleteAfterReplies > 1 ? 'cant-delete-topic-has-replies' : 'cant-delete-topic-has-reply';
-				return callback(new Error('[[error:' + langKey + ', ' + meta.config.preventTopicDeleteAfterReplies + ']]'));
+				var langKey = preventTopicDeleteAfterReplies > 1 ?
+					'[[error:cant-delete-topic-has-replies, ' + meta.config.preventTopicDeleteAfterReplies + ']]':
+					'[[error:cant-delete-topic-has-reply]]';
+				return callback(new Error(langKey));
 			}
 
 			if (!results['topics:delete'][0]) {