Forge app error “No mime type could be found for file favicon.ico”

Apps generated using JBoss Forge get this error showing up in the server log:

JSF1091: No mime type could be found for file favicon.ico.  To resolve this, add a mime-type mapping to the applications web.xml

This is described in this bug: https://issues.jboss.org/browse/FORGE-657

The quick fix is to add this to your web.xml:

<mime-mapping>
   <extension>ico</extension>
   <mime-type>image/x-icon</mime-type>
</mime-mapping>