found some other places with the same problem

src/controllers/admin/uploads.js

@@ -114,7 +114,7 @@ function validateUpload(req, res, next, uploadedFile, allowedTypes) {
 			}
 		});
 
-		res.json({error: '[[error:invalid-image-type, ' + allowedTypes.join(', ') + ']]'});
+		res.json({error: '[[error:invalid-image-type, ' + allowedTypes.join(', ') + ']]'});
 		return false;
 	}
 

src/socket.io/user/picture.js

@@ -23,7 +23,7 @@ module.exports = function(SocketUser) {
 		} else if (type === 'uploaded') {
 			type = 'uploadedpicture';
 		} else {
-			return callback(new Error('[[error:invalid-image-type, ' + ['gravatar', 'uploadedpicture'].join(', ') + ']]'));
+			return callback(new Error('[[error:invalid-image-type, ' + ['gravatar', 'uploadedpicture'].join(', ') + ']]'));
 		}
 
 		async.waterfall([