Fix bash array syntax

Closes #64 (closed)

.gitlab-ci.yml

@@ -40,6 +40,12 @@ build_image:
   tags:
     - build
   script:
+    - |
+      SERVER_TO_BE_DELETE=($(openstack server list --name ood-knightly --sort-column Image --sort-descending -f value -c ID | sed -n $(($NUM_SERVER_TO_KEEP+1))',$p'))
+      for svr in ${SERVER_TO_BE_DELETE[@]}; do
+        echo server delete ${svr}
+      done
+      exit 1
     - |
       if [ ! -d $CI_PROJECT_DIR/CRI_XCBC ]; then
         git clone https://github.com/uabrc/CRI_XCBC.git