add check if there is something to failover

failover.ps1

@@ -4,6 +4,12 @@ $nodeList = docker node ls --format '{{json .}}'| ConvertFrom-Json | ForEach-Obj
     docker node inspect $_.ID | ConvertFrom-Json
 }
 $onlineNodeList = $nodeList | Where-Object {$_.Spec.Availability -eq 'active'}
+$offlineNodeList = $nodeList | Where-Object {$_.Spec.Availability -ne 'active'}
+
+if (!$offlineNodeList.Count) {
+    Write-Output 'all hosts online, nothing to failover'
+    exit
+}
 
 $failoverAddressList = (Invoke-RestMethod -Uri 'https://robot-ws.your-server.de/failover' -Authentication Basic -Credential $hetznerCredentials).failover
 $offlineAddressList = $failoverAddressList | Where-Object active_server_ip -notin $onlineNodeList.Status.Addr