[alertmanager] fix broken pdb due to missing line break (prometheus-community#2796)

Author: toVersus

charts/alertmanager/Chart.yaml

@@ -6,7 +6,7 @@ icon: https://raw.githubusercontent.com/prometheus/prometheus.github.io/master/a
 sources:
   - https://github.com/prometheus/alertmanager
 type: application
-version: 0.22.1
+version: 0.22.2
 appVersion: v0.24.0
 maintainers:
   - name: monotek

charts/alertmanager/templates/pdb.yaml

@@ -9,5 +9,5 @@ spec:
   selector:
     matchLabels:
       {{- include "alertmanager.selectorLabels" . | nindent 6 }}
-  {{- toYaml .Values.podDisruptionBudget | indent 2 }}
+  {{- toYaml .Values.podDisruptionBudget | nindent 2 }}
 {{- end }}