Also provide a "proper" java.util.logger logger to plugins.

proxy/src/main/java/com/velocitypowered/proxy/plugin/loader/java/VelocityPluginModule.java

@@ -31,6 +31,8 @@ class VelocityPluginModule implements Module {
     binder.bind(description.getMainClass()).in(Scopes.SINGLETON);
 
     binder.bind(Logger.class).toInstance(LoggerFactory.getLogger(description.getId()));
+    binder.bind(java.util.logging.Logger.class)
+        .toInstance(java.util.logging.Logger.getLogger(description.getId()));
     binder.bind(Path.class).annotatedWith(DataDirectory.class)
         .toInstance(basePluginPath.resolve(description.getId()));
     binder.bind(PluginDescription.class).toInstance(description);