OZG-5681 add required configurations

vorgang-manager-server/src/main/resources/application.yml

@@ -71,6 +71,9 @@ ozgcloud:
     mail-from: EA-Poststelle@itvsh.de
   notification:
     mail-from: hilfe@ozgcloud.support
+  nachrichten-manager:
+    address: self:self
+    negotiation-type: plaintext
 #  vorgang-manager:
 #    address: self:self
 #    negotiation-type: plaintext