url rewriting doesnt work in wildfly 8.2.1

I have an application running on wildfly 8.2.1 which is upgraded from jboss 6.4. for URL rewriting in jboss 6.4 , we have virtual server section in standlone-full.xml however to do the same on wildfly 8.2.1 its been suggested to write the rule in undertow-handlers.conf and put the same in WEB-INF directory ,however that is not working.Basically i want to rewrite http://ip_address/a and http://ip_address/b to http://ip_address/c , to do the same i have written below rule in undertow-handlers.conf it is not working, regex['^/a/$'] -> rewrite['/c/$1']. Can anyone tell if am doing anything wrong , similiar rule used to work in JBOSS 6.4