fixed build error

app/app.component.ts

@@ -32,7 +32,7 @@ export class AppComponent extends OnInit {
             let result:string;
             try {
                 result = converter.convert(content);
-            } catch (error:Error) {
+            } catch (error) {
                 if (typeof console === "object" && typeof console.log === "function") {
                     console.log(error);
                 }