remove "magic" route fallback to the first section

src/Umbraco.Web.UI.Client/src/apps/backoffice/components/backoffice-main.element.ts

@@ -64,22 +64,6 @@ export class UmbBackofficeMainElement extends UmbLitElement {
 				}
 			});
 
-		if (this._sections.length > 0) {
-			const fallbackSectionPath = UMB_SECTION_PATH_PATTERN.generateLocal({
-				sectionName: this._sections[0].manifest!.meta.pathname,
-			});
-			this._routes.push({
-				alias: '__redirect',
-				path: '/',
-				redirectTo: fallbackSectionPath,
-			});
-			this._routes.push({
-				alias: '__redirect',
-				path: '/section/',
-				redirectTo: fallbackSectionPath,
-			});
-		}
-
 		this.requestUpdate('_routes', oldValue);
 	}