Warnings in the console about using ":" in a JMX object name when deleting an attachment from the default wiki skin

2019-06-20 11:50:20,700 [http://localhost:8080/xwiki/bin/delattachment/XWiki/DefaultSkin/icons.xwiki.favicon.ico?form_token=5UgrVOpRhw04k3g6ZEhgEQ&xredirect=%2Fxwiki%2Fbin%2Fview%2FXWiki%2FDefaultSkin%23Attachments] WARN  m.i.DefaultJMXBeanRegistration - Failed to unregister resource with name [type=Velocity,domain=Engines,name=xwiki:XWiki.DefaultSkin@icons.xwiki.favicon.ico]. Reason = [MalformedObjectNameException: Invalid character ':' in value part of property] 
2019-06-20 11:50:52,663 [http://localhost:8080/xwiki/bin/delattachment/XWiki/DefaultSkin/icons.xwiki.favicon16.png?form_token=5UgrVOpRhw04k3g6ZEhgEQ&xredirect=%2Fxwiki%2Fbin%2Fview%2FXWiki%2FDefaultSkin%23Attachments] WARN  m.i.DefaultJMXBeanRegistration - Failed to unregister resource with name [type=Velocity,domain=Engines,name=xwiki:XWiki.DefaultSkin@icons.xwiki.favicon16.png]. Reason = [MalformedObjectNameException: Invalid character ':' in value part of property] 
2019-06-20 13:34:26,450 [http://localhost:8080/xwiki/bin/delattachment/XWiki/DefaultSkin/icons.xwiki.favicon16.png?form_token=5UgrVOpRhw04k3g6ZEhgEQ&xredirect=%2Fxwiki%2Fbin%2Fview%2FXWiki%2FDefaultSkin%23Attachments] WARN  m.i.DefaultJMXBeanRegistration - Failed to unregister resource with name [type=Velocity,domain=Engines,name=xwiki:XWiki.DefaultSkin@icons.xwiki.favicon16.png]. Reason = [MalformedObjectNameException: Invalid character ':' in value part of property] 
2019-06-20 13:47:39,513 [http://localhost:8080/xwiki/bin/delattachment/XWiki/DefaultSkin/icons.xwiki.favicon.ico?form_token=5UgrVOpRhw04k3g6ZEhgEQ&xredirect=%2Fxwiki%2Fbin%2Fview%2FXWiki%2FDefaultSkin%23Attachments] WARN  m.i.DefaultJMXBeanRegistration - Failed to unregister resource with name [type=Velocity,domain=Engines,name=xwiki:XWiki.DefaultSkin@icons.xwiki.favicon.ico]. Reason = [MalformedObjectNameException: Invalid character ':' in value part of property]