verify all system accounts are set

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>
(cherry picked from commit 972adafd29)

services/proxy/pkg/config/parser/parse.go

@@ -53,5 +53,12 @@ func Validate(cfg *config.Config) error {
 		)
 	}
 
+	if cfg.ServiceAccount.ServiceAccountID == "" {
+		return shared.MissingServiceAccountID(cfg.Service.Name)
+	}
+	if cfg.ServiceAccount.ServiceAccountSecret == "" {
+		return shared.MissingServiceAccountSecret(cfg.Service.Name)
+	}
+
 	return nil
 }