jsonnet: remove superfluous quotation mark

jsonnet/kube-prometheus/components/mixin/alerts/node.libsonnet

@@ -7,7 +7,7 @@
           {
             alert: 'NodeNetworkInterfaceFlapping',
             annotations: {
-              message: 'Network interface "{{ $labels.device }}" changing it\'s up status often on node-exporter {{ $labels.namespace }}/{{ $labels.pod }}"',
+              message: 'Network interface "{{ $labels.device }}" changing it\'s up status often on node-exporter {{ $labels.namespace }}/{{ $labels.pod }}',
             },
             expr: |||
               changes(node_network_up{%(nodeExporterSelector)s,%(hostNetworkInterfaceSelector)s}[2m]) > 2