Updated to angular 11

Now compiling with strict mode in typescript
Need to error checking now

bookie/src/app/section-printers/section-printer.service.ts

@@ -18,7 +18,7 @@ const serviceName = 'SectionPrinterService';
 export class SectionPrinterService {
   constructor(private http: HttpClient, private log: ErrorLoggerService) {}
 
-  get(id: string): Observable<SectionPrinter[]> {
+  get(id: string | null): Observable<SectionPrinter[]> {
     const getUrl: string = id === null ? `${url}` : `${url}/${id}`;
     return <Observable<SectionPrinter[]>>(
       this.http