[1151441] JON server was unexpectedly stopped
Only resolve the identity of the running server (i.e. the SERVER_NAME) one
time and cache it as a static for ServerManagerBean.  This is more efficient
as the server name can not change at runtime, and actually should not change
for a defined server, ever, in general.  Moreover, for server where
rhq.server.high-availability.name is not set, it prevents repeated calls to
InetAddress.getLocalhost(), which can fail if there is a temporary DNS
issue, and the localhost can not be resolved.

(cherry picked from commit 4e66a36bd3be3d4d670bf161121988f255fdbeeb)
Signed-off-by: Jay Shaughnessy <jshaughn@redhat.com>