OZG-5044 tiny cleanup

...ava/de/ozgcloud/admin/settings/DataRestConfiguration.java

...ain/java/de/ozgcloud/admin/settings/SettingConstants.java

src/main/java/de/ozgcloud/admin/settings/SettingMapper.java

...in/java/de/ozgcloud/admin/settings/SettingRepository.java

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

...in/java/de/ozgcloud/admin/settings/postfach/Absender.java

...ozgcloud/admin/settings/postfach/PostfachSettingBody.java

src/test/java/de/ozgcloud/admin/settings/SettingITCase.java

...ud/admin/settings/postfach/PostfachSettingBodyITCase.java