Bug 1124845 - EAP6 with secured management - confusing error msg when incorrect Truststore Type is set

Now trying to load the truststore/keystore when validating the
connection settings and retun correct message in case of failure

(cherry picked from commit 62986312e18a2f02e7336fe33acdbd535b85016a)
Signed-off-by: Jirka Kremser <jkremser@redhat.com>