fix: type error

Author: caebr

src/app/components/Editor.tsx

@@ -165,7 +165,7 @@ export default function Editor() {
 
   const organisations = organisationData.flatMap(data =>
     data.organisations.map(organisation => ({
-      text: getLocalizedText(organisation.name, i18n.language) + (organisation.alternativeName ? ` (${getLocalizedText(organisation.alternativeName, i18n.language)})` : ""),
+      text: getLocalizedText(organisation.name, i18n.language) + ('alternativeName' in organisation && organisation.alternativeName ? ` (${getLocalizedText(organisation.alternativeName, i18n.language)})` : ""),
       value: organisation.id,
       group: getLocalizedText(data.name, i18n.language) + (data.abbreviation ? ` (${getLocalizedText(data.abbreviation, i18n.language)})` : ''),
     })).sort((a, b) => a.text.localeCompare(b.text, i18n.language))