Update docker-compose.yml: restore image tags to be branch name

melodic_properties/templates/melodicStack/docker-compose.yml

@@ -501,7 +501,7 @@ services:
     networks:
       - elk
   gui-backend:
-    image: gitlab.ow2.org:4567/melodic/melodic-upperware/gui-backend:ftt
+    image: gitlab.ow2.org:4567/melodic/melodic-upperware/gui-backend:${IMAGE_BRANCH}
     logging:
       driver: journald
       options:
@@ -523,7 +523,7 @@ services:
     networks:
       - elk
   functionizer-testing-tool:
-    image: gitlab.ow2.org:4567/melodic/melodic-upperware/functionizer-testing-tool:ftt
+    image: gitlab.ow2.org:4567/melodic/melodic-upperware/functionizer-testing-tool:${IMAGE_BRANCH}
     logging:
       driver: journald
       options:
@@ -544,7 +544,7 @@ services:
       - elk
   # nginx server with user interface
   gui-frontend:
-    image: gitlab.ow2.org:4567/melodic/melodic-frontend:ftt
+    image: gitlab.ow2.org:4567/melodic/melodic-frontend:${IMAGE_BRANCH}
     logging:
       driver: journald
       options: