Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=54371
Prevent exceptions when processing web fragments for unexpanded WAR files when the context path contains characters that need to be encoded in URLs such as spaces.
Patch provided by Polina Genova.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1429858 13f79535-47bb-0310-9956-ffa450edef68