OZG-5044 Recovered default for application settings

src/main/java/de/ozgcloud/admin/setting/Setting.java

@@ -24,7 +24,6 @@ package de.ozgcloud.admin.setting;
 import jakarta.validation.Valid;
 
 import org.springframework.data.annotation.Id;
-import org.springframework.data.annotation.TypeAlias;
 import org.springframework.data.mongodb.core.mapping.Document;
 
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
@@ -38,7 +37,6 @@ import lombok.extern.jackson.Jacksonized;
 @Getter
 @Jacksonized
 @Document(Setting.COLLECTION_NAME)
-@TypeAlias("de.ozgcloud.admin.settings.Settings")
 public class Setting {
 	static final String COLLECTION_NAME = "settings";
 

src/main/java/de/ozgcloud/admin/setting/SettingService.java

@@ -26,6 +26,6 @@ class SettingService {
 
 	PostfachSettingBody getSettingWithPostfachFromDb() {
 		var postfach = repository.findOneByName(POSTFACH_SETTING_ITEM_NAME);
-		return postfach.map(Setting::getSettingBody).map(PostfachSettingBody.class::cast).orElse(PostfachSettingBody.builder().build());
+		return postfach.isPresent() ? (PostfachSettingBody) postfach.get().getSettingBody() : PostfachSettingBody.builder().build();
 	}
 }