Fix nuxeoctl incompatibility with JDK 11 on Windows

Since NXP-24210, JDK 11 is supported in Nuxeo (fixed in 10.3)
lib/tools.jar is not shipped with JDK 11 anymore and nuxeoctl thus refuses to boot Nuxeo.

The simple fact to create an empty file as JDK11/lib/tool.jar enables to boot.

Fix nuxeoctl so that it does not check for lib/tools.jar existence

Symptom:

Found NUXEO_CONF = C:\Boulot\Nuxeo10.3\nuxeo-server-10.3-tomcat\bin\nuxeo.conf
Found JAVA_HOME = c:\jdks\jdk-11.0.1
Could not find tools.jar in JAVA_HOME\lib. Please fix or remove JAVA_HOME; ensure JDK is properly installed.