[incubator/cassandra] Replaces '_' with '-' in keyspace name when constructing a CronJob name (#12181)

Signed-off-by: Anders Nordström <anders.nordstrom@barium.se>

incubator/cassandra/Chart.yaml

@@ -1,5 +1,5 @@
 name: cassandra
-version: 0.10.4
+version: 0.10.5
 appVersion: 3.11.3
 description: Apache Cassandra is a free and open-source distributed database management
   system designed to handle large amounts of data across many commodity servers, providing

incubator/cassandra/templates/backup/cronjob.yaml

@@ -7,7 +7,7 @@
 apiVersion: batch/v1beta1
 kind: CronJob
 metadata:
-  name: {{ template "cassandra.fullname" $ }}-backup-{{ $schedule.keyspace }}
+  name: {{ template "cassandra.fullname" $ }}-backup-{{ $schedule.keyspace | replace "_" "-" }}
   labels:
     app: {{ template "cassandra.name" $ }}-cain
     chart: {{ template "cassandra.chart" $ }}