1153010 - move verifyOrgExists method to BaseHandler as it is being called from more handlers

main intention is to remove the 'public' keyword as the method gets included into the APIdoc
remove unnecessarily nested 'else' statement
remove unnecessarily nested 'else' statement
remove unnecessarily nested 'else' statement
remove @Override annotation from method that isn't overriden
Automatic commit of package [spacewalk-java] release [2.3.75-1].