QA-6678 - Compilation error for modules with a internal tag library and tag files
https://jira.jahia.org/browse/QA-6678

Applied the fix, found in "GLASSFISH-18391 - NPE in TagLibraryInfoImpl createTagFileInfo" (https://java.net/jira/browse/GLASSFISH-18391): added a check for JAR URL to be non-null before adding it.