Moved pdf creatior initialization to new function

ref #5

src/controllers/PdfController.ts

@@ -10,10 +10,7 @@ import { PdfCreator } from '../PdfCreator';
  */
 @JsonController()
 export class PdfController {
-    private pdf: PdfCreator;
-    constructor() {
-        this.pdf = new PdfCreator();
-    }
+    private pdf: PdfCreator = new PdfCreator();
 
     @Post('/contracts')
     @OpenAPI({ description: "Generate Sponsoring contract pdfs from runner objects.<br>You can choose your prefered locale by passing the 'locale' query-param." })