Add confirmation to error message
Add confirmation to error message

xorphitus/mackerel-agent-plugins,y-kuno/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,ki38sato/mackerel-agent-plugins,y-kuno/mackerel-agent-plugins,ki38sato/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,y-kuno/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,ki38sato/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,y-kuno/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,ki38sato/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins