Avoid the use of --force in groupadd

According to the man page, --force may ignore --gid and this is
not what we want.
With our ID system it is almost impossible that we hit this issue
but better be safe than sorry. ;-)

Change-Id: I359982ddd144e07f8296b384638cf0b5331e495c

Author: yoctozepto

docker/base/Dockerfile.j2

@@ -21,7 +21,7 @@ ENV LANG en_US.UTF-8
 {# Specifics required such as homedir or shell are configured within the service specific image #}
 {%- for name, user in users | dictsort() %}
 {% if loop.first -%}RUN {% else %}    && {% endif -%}
-    groupadd --force --gid {{ user.gid }} {{ user.group }} \
+    groupadd --gid {{ user.gid }} {{ user.group }} \
     && useradd -l -M --shell /usr/sbin/nologin --uid {{ user.uid }} --gid {{ user.gid }} {{ name }}
         {%- if not loop.last %} \{% endif -%}
 {%- endfor %}

kolla/common/config.py

@@ -758,7 +758,7 @@
     },
     'mongodb-user': {  # unused user (mongodb dropped)
         'uid': 42432,
-        'gid': 65534,
+        'gid': 42432,
     },
     'murano-user': {
         'uid': 42433,