Modifying the META-INF/MANIFEST.MF is not the best solution.
I recommand this one :
Create a 'WEB-INF/jboss-deployment-structure.xml' which contains a dependency to 'org.jboss.security.negotiation'.
Like this :
<jboss-deployment-structure>
<deployment>
<dependencies>
<module name="org.jboss.security.negotiation" />
</dependencies>
</deployment>
</jboss-deployment-structure>