prevent crash if data.enter is not string

public/src/app.js

@@ -92,7 +92,7 @@ app.cacheBuster = null;
 
 			switch(url_parts[0]) {
 				case 'user':
-					room = 'user/' + ajaxify.data ? ajaxify.data.theirid : 0;
+					room = 'user/' + (ajaxify.data ? ajaxify.data.theirid : 0);
 				break;
 				case 'topic':
 					room = 'topic_' + url_parts[1];

src/socket.io/meta.js

@@ -59,6 +59,10 @@ SocketMeta.rooms.enter = function(socket, data, callback) {
 		return callback(new Error('[[error:invalid-data]]'));
 	}
 
+	if (data.enter) {
+		data.enter = data.enter.toString();
+	}
+
 	if (data.enter && data.enter.startsWith('uid_') && data.enter !== 'uid_' + socket.uid) {
 		return callback(new Error('[[error:not-allowed]]'));
 	}