Refactor image repository to a single variable

salt/common/tools/sbin/so-common

@@ -15,6 +15,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+IMAGEREPO=soshybridhunter
+
 # Check for prerequisites
 if [ "$(id -u)" -ne 0 ]; then
         echo "This script must be run using sudo!"