Set history-max to 10 by default (#6421)

It makes sense to limit the history by default. Setting
it to 10 aligns with the default for a ReplicaSet's
`revisionHistoryLimit`.

Fixes: #5157
Signed-off-by: Reinhard Naegele <unguiculus@gmail.com>

cmd/helm/upgrade.go

@@ -153,7 +153,7 @@ func newUpgradeCmd(cfg *action.Configuration, out io.Writer) *cobra.Command {
 	f.BoolVar(&client.ReuseValues, "reuse-values", false, "when upgrading, reuse the last release's values and merge in any overrides from the command line via --set and -f. If '--reset-values' is specified, this is ignored.")
 	f.BoolVar(&client.Wait, "wait", false, "if set, will wait until all Pods, PVCs, Services, and minimum number of Pods of a Deployment, StatefulSet, or ReplicaSet are in a ready state before marking the release as successful. It will wait for as long as --timeout")
 	f.BoolVar(&client.Atomic, "atomic", false, "if set, upgrade process rolls back changes made in case of failed upgrade. The --wait flag will be set automatically if --atomic is used")
-	f.IntVar(&client.MaxHistory, "history-max", 0, "limit the maximum number of revisions saved per release. Use 0 for no limit.")
+	f.IntVar(&client.MaxHistory, "history-max", 10, "limit the maximum number of revisions saved per release. Use 0 for no limit.")
 	addChartPathOptionsFlags(f, &client.ChartPathOptions)
 	addValueOptionsFlags(f, valueOpts)