Merge pull request #49278 from juju-solutions/bug/master-msg

Automatic merge from submit-queue (batch tested with PRs 49330, 49252, 49262, 49278, 49334)

Simplify master-worker relation missing message

**What this PR does / why we need it**: Simplify messaging of missing relation in Juju deployments

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes https://github.com/juju-solutions/bundle-canonical-kubernetes/issues/309

**Special notes for your reviewer**:

**Release note**:

```NONE
```

cluster/juju/layers/kubernetes-master/reactive/kubernetes_master.py

@@ -398,17 +398,14 @@ def send_tokens(kube_control):
 
 @when_not('kube-control.connected')
 def missing_kube_control():
-    """Inform the operator they need to add the kube-control relation.
+    """Inform the operator master is waiting for a relation to workers.
 
     If deploying via bundle this won't happen, but if operator is upgrading a
     a charm in a deployment that pre-dates the kube-control relation, it'll be
     missing.
 
     """
-    hookenv.status_set(
-        'blocked',
-        'Relate {}:kube-control kubernetes-worker:kube-control'.format(
-            hookenv.service_name()))
+    hookenv.status_set('blocked', 'Waiting for workers.')
 
 
 @when('kube-api-endpoint.available')