Upgrade to MySQL 8

Workaround for exception thrown by ResultSet#beforeFirst():
"Operation not allowed for a result set of type ResultSet.TYPE_FORWARD_ONLY"

src/main/java/net/server/Server.java

@@ -1620,7 +1620,9 @@ public class Server {
     
     private static void applyAllWorldTransfers() {
         try (Connection con = DatabaseConnection.getConnection();
-                PreparedStatement ps = con.prepareStatement("SELECT * FROM worldtransfers WHERE completionTime IS NULL")) {
+                PreparedStatement ps = con.prepareStatement("SELECT * FROM worldtransfers WHERE completionTime IS NULL",
+                        ResultSet.TYPE_SCROLL_SENSITIVE,
+                        ResultSet.CONCUR_READ_ONLY)) {
             ResultSet rs = ps.executeQuery();
             List<Integer> removedTransfers = new LinkedList<Integer>();
             while(rs.next()) {