code: func (configFile *ConfigFile) SetPluginConfig(pluginname, option, value string) {
  	if configFile.Plugins == nil {
  		configFile.Plugins = make(map[string]map[string]string)
  	}
  	pluginConfig, ok := configFile.Plugins[pluginname]
  	if !ok {
  		pluginConfig = make(map[string]string)
  		configFile.Plugins[pluginname] = pluginConfig
  	}
  	if value != "" {
  		pluginConfig[option] = value
  	} else {
  		delete(pluginConfig, option)
  	}
  	if len(pluginConfig) == 0 {
  		delete(configFile.Plugins, pluginname)
  	}
  }
docs: // SetPluginConfig sets the option to the given value for the given
  // plugin. Passing a value of "" will remove the option. If removing
  // the final config item for a given plugin then also cleans up the
  // overall plugin entry.