Fix typescript error.

resources/js/components/ProcessFile/ProcessFile.ts

@@ -428,7 +428,7 @@ export default class ProcessFile extends Vue {
             });
         });
 
-        let response = await this.$api.convertFile(this.processedFileContent, {id: this.file.id, name: this.file.file_name}, searchers);
+        let response = await this.$api.convertFile(this.processedFileContent, {id: this.file.id, name: this.file.file_name || 'filename.odt'}, searchers);
 
         window.open(`${window.location.origin}/file/download/` + response.path);
     }