title: Grails - override a bean property value in resources.groovy
body: <p>There's a <code>messageSource</code> bean defined in the Grails i18n plugin <a href="https://github.com/grails/grails-core/blob/master/grails-plugin-i18n/src/main/groovy/org/codehaus/groovy/grails/plugins/i18n/I18nGrailsPlugin.groovy#L71" rel="nofollow">defined thusly</a>:</p>
  
  <pre><code>messageSource(PluginAwareResourceBundleMessageSource) {
    basenames = baseNames.toArray()
    fallbackToSystemLocale = false
    pluginManager = manager
    ....
  }
  </code></pre>
  
  <p>Is it possible to override the configuration of just the <code>fallbackToSystemLocale</code> value from my resources.groovy, something like: </p>
  
  <pre><code>messageSource {
      fallbackToSystemLocale = true
  } 
  </code></pre>
  
  <p>The above doesn't work, I get an error: "Error creating bean with name 'messageSource': Bean definition is abstract"</p>