BZ 56661: Fix Servlet API getLocalAddr().

Use new custom request attribute "AJP_LOCAL_ADDR"
forwarded by the next mod_jk 1.2.41 to set the local
IP address returned by getLocalAddr():

Before this change Tomcat handled getLocalAddr() like
getLocalName().

Backport of r1609593 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1609606 13f79535-47bb-0310-9956-ffa450edef68