Migrate JodaTime usage in several database handlers to java.time.*

src/engine/db/handlers/dbMobHandler.java

@@ -12,7 +12,7 @@ package engine.db.handlers;
 import engine.gameManager.DbManager;
 import engine.objects.Mob;
 import engine.objects.Zone;
-import org.joda.time.DateTime;
+import java.time.Instant;
 import org.pmw.tinylog.Logger;
 
 import java.sql.Connection;
@@ -69,7 +69,7 @@ public class dbMobHandler extends dbHandlerBase {
         return mobile;
     }
 
-    public boolean updateUpgradeTime(Mob mob, DateTime upgradeDateTime) {
+    public boolean updateUpgradeTime(Mob mob, Instant upgradeDateTime) {
 
         try (Connection connection = DbManager.getConnection();
              PreparedStatement preparedStatement = connection.prepareStatement("UPDATE obj_mob SET upgradeDate=? "
@@ -78,7 +78,7 @@ public class dbMobHandler extends dbHandlerBase {
             if (upgradeDateTime == null)
                 preparedStatement.setNull(1, java.sql.Types.DATE);
             else
-                preparedStatement.setTimestamp(1, new java.sql.Timestamp(upgradeDateTime.getMillis()));
+                preparedStatement.setTimestamp(1, java.sql.Timestamp.from(upgradeDateTime));
 
             preparedStatement.setInt(2, mob.getObjectUUID());