root: use %{x} notation instead of ${x} in web.xml

rhel jboss, at least 7.1.3-4, perform unconditional properties ${x}
substitutions in web.xml, while fedora jboss at least 7.1.1-9.3, does
not.

a solution for rhel jboss is to use $${x}, while this solution is not
working for fedora jboss.

to allow common processing and future migration to other application
server the notation was changed to %{x}.

Related-Change-Id: I94f845d36bb075c238e50606187bc22316713cdd
Change-Id: I115118e6f46ac74bc882949e101bbe3d04e29684
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>