Update metadata only if it is changed

Signed-off-by: Lauri Nevala <lauri.nevala@gmail.com>

src/main/routes/metrics-route.ts

@@ -73,9 +73,11 @@ class MetricsRoute extends LensApi {
       prometheusMetadata["success"] = false
       this.respondJson(response, {})
     } finally {
+      if (JSON.stringify(cluster.metadata[ClusterMetadataKey.PROMETHEUS]) !== JSON.stringify(prometheusMetadata)) {
         cluster.metadata[ClusterMetadataKey.PROMETHEUS] = prometheusMetadata
       }
     }
+  }
 }
 
 export const metricsRoute = new MetricsRoute()