fix: only check host keys on requested hosts

See coop-cloud/organising#242.

cli/app/list.go

@@ -8,6 +8,7 @@ import (
 	abraFormatter "coopcloud.tech/abra/cli/formatter"
 	"coopcloud.tech/abra/pkg/catalogue"
 	"coopcloud.tech/abra/pkg/config"
+	"coopcloud.tech/abra/pkg/ssh"
 	"coopcloud.tech/tagcmp"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
@@ -69,6 +70,12 @@ can take some time.
 		}
 		sort.Sort(config.ByServerAndType(apps))
 
+		for _, app := range apps {
+			if err := ssh.EnsureHostKey(app.Server); err != nil {
+				logrus.Fatal(err)
+			}
+		}
+
 		statuses := make(map[string]map[string]string)
 		tableCol := []string{"Server", "Type", "Domain"}
 		if status {