Check if repos backup exists in kolla footer

When a child service is build, such as neutron-infoblox-ipam-agent
being a child of neutron-server, the fotoer is ran twice.

This means it fails as the repo backup has already been moved.

Author: MoteHue

etc/kayobe/kolla.yml

@@ -351,14 +351,17 @@ kolla_build_blocks:
   footer: |
     {% if stackhpc_kolla_clean_up_repo_mirrors | bool %}
     {% if kolla_base_distro in ['centos', 'rocky'] %}
+    {% if [ -f /etc/yum.repos.d.backup/repos.tar.gz ] %}
     RUN \
         tar -xzf /etc/yum.repos.d.backup/repos.tar.gz -C /etc/yum.repos.d && \
         if grep -r '{{ stackhpc_repo_mirror_url }}' /etc/yum.repos.d; then \
            echo "Found repository mirror in Yum repositories"; \
            exit 1; \
         fi && \
         rm -rf /etc/yum.repos.d.backup/
+    {% endif %}
     {% else %}
+    {% if [ -f /etc/apt/sources.list.backup ] %}
     RUN \
         mv /etc/apt/sources.list.backup /etc/apt/sources.list && \
         if grep -r '{{ stackhpc_repo_mirror_url }}' /etc/apt/sources.list; then \
@@ -367,6 +370,7 @@ kolla_build_blocks:
         fi
     {% endif %}
     {% endif %}
+    {% endif %}
   bifrost_base_header: |
     ADD additions-archive /
   grafana_plugins_install: |