New translations validations.properties (English, Nigeria)

sormas-api/src/main/resources/validations_en-NG.properties

@@ -292,7 +292,7 @@ defaultInfrastructureInvalidParentDistrict = This community is in a different di
 defaultInfrastructureNotRemovableChildCommunity = You have to remove the default community before removing the default district.
 defaultInfrastructureNotRemovableChildDistrict = You have to remove the default district before removing the default region.
 emailTemplateSubjectInvalid=The first line of the email template needs to start with a "\#" character followed by at most 50 characters
-customizableEnumValueAllowedCharacters = Value may only consist of uppercase letters, numbers, and the characters "_" and ".".
+customizableEnumValueAllowedCharacters = Value may only consist of uppercase letters, numbers, and the characters "_", "." and "+".
 customizableEnumValueEmptyTranslations = Please select languages and enter captions for all translations in the list.
 customizableEnumValueDuplicateLanguage = Please only add one translation per language.
 customizableEnumValueDuplicateValue = The value %s already exists for data type %s. Enum values have to be unique.