[KARAF-2511] Add a note about karaf.secured.services in the security section of the user guide
[KARAF-2511] Add a note about karaf.secured.services in the security section of the user guide

git-svn-id: 71d8a689455c5fbb0f077bc40adcfc391e14cb9d@1550132 13f79535-47bb-0310-9956-ffa450edef68

grgrzybek/karaf,grgrzybek/karaf,grgrzybek/karaf