Fix TLD processing when using JspC.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1530971 13f79535-47bb-0310-9956-ffa450edef68
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55251
Do not allow JspC task to fail silently if the web.xml or web.xml fragment can not be generated. 

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1530975 13f79535-47bb-0310-9956-ffa450edef68