[mysql] prefer strings.HasPrefix to strings.Index == 0
[mysql] prefer strings.HasPrefix to strings.Index == 0

hiroakis/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,ariarijp/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins,xorphitus/mackerel-agent-plugins,hiroakis/mackerel-agent-plugins,mackerelio/mackerel-agent-plugins