Fix #1929: Suppress logging hibernate internals (#2158)

* chore: suppress logging of hibernate internals

* chore: use non-obsolete hibernate namespace

metadata-mapping/README.md

@@ -104,7 +104,7 @@ We use `Hibernate` to resolve the mapping and connect to our database, here's it
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE hibernate-configuration PUBLIC
     "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
-    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
+    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
 <hibernate-configuration>
   <session-factory>
     <!-- JDBC Database connection settings -->