Fix Studio hotreload when NUXEO_HOME is set with a symbolic link

Unzip your Nuxeo under /opt/nuxeo-cap-5.6-tomcat
Create a symbolic link from /opt/nuxeo-cap-5.6-tomcat to /opt/nuxeo
Set NUXEO_HOME environment variable to /opt/nuxeo
Start Nuxeo and try to hotreload a Studio package

=> this will fail because the system won't find the target bundle
UpdateManager#getRollbackTarget(opts) will return null (JarUtils#findJar(File root, String key) cannot find the bundle under the symbolic path = root = Environment#initServerHome), so no component reload will be done

This line will not be present while hot-reloading Studio package

INFO  [ReloadComponent] Deploy done for bundle with name 'studio.extensions.xxx'.