doc: README: add trust store note
doc: README: add trust store note

Change-Id: Ie0c9dc87795fb716819f0bfb8002ae3b1b92d5ea
Signed-off-by: Alon Bar-Lev <2e3ceb4d37adc6ae3ccc00d3646e0e0a036ace03@redhat.com>

alonbl/ovirt-engine-extension-aaa-ldap,alonbl/ovirt-engine-extension-aaa-ldap,alonbl/ovirt-engine-extension-aaa-ldap,oVirt/ovirt-engine-extension-aaa-ldap,oVirt/ovirt-engine-extension-aaa-ldap,oVirt/ovirt-engine-extension-aaa-ldap