fix(connections): Remove securityContext causing container startup failure

The signal-cli-rest-api container's entrypoint script requires
privileges to modify user/group settings. Removing securityContext
allows the container to run with its default settings.

cluster/platform/connections/deployment.yaml

@@ -20,10 +20,6 @@ spec:
         app.kubernetes.io/name: connections
         app.kubernetes.io/component: messaging-gateway
     spec:
-      securityContext:
-        fsGroup: 1000
-        runAsUser: 1000
-        runAsNonRoot: true
       containers:
       - name: signal-cli-rest-api
         image: bbernhard/signal-cli-rest-api:0.85  # Pin version, test upgrades