Fix openstack-congress package name

Fix openstack-congress package name

JIRA: APEX-287

openstack-congress rpm-spec use '%dist' macro as name
suffix, '%dist' macro is different over various distros
which may cause name mismatch when uploading package to
overcloud images; fix it by using '%dist' macro in
package name to avoid possible mismatch.

Change-Id: Iaa7068d7da3e5fe3728baf2fa3c67eb45355c74a
Signed-off-by: zshi <zshi@redhat.com>