fix(module): force init

Author: Raphaël Balet

projects/ngx-back-button/src/lib/ngx-back-button.module.ts

@@ -1,4 +1,4 @@
-import { ModuleWithProviders, NgModule } from '@angular/core'
+import { APP_INITIALIZER, ModuleWithProviders, NgModule } from '@angular/core'
 import { NgxBackButtonServiceProvider } from './ngx-back-button.const'
 import { NgxBackButtonDirective } from './ngx-back-button.directive'
 import { NgxBackButtonServiceConfig } from './ngx-back-button.interface'
@@ -13,11 +13,16 @@ export class NgxBackButtonModule {
     return {
       ngModule: NgxBackButtonModule,
       providers: [
-        NgxBackButtonService,
         {
           provide: NgxBackButtonServiceProvider,
           useValue: config,
         },
+        {
+          provide: APP_INITIALIZER,
+          useFactory: (service: NgxBackButtonService) => () => service,
+          deps: [NgxBackButtonService],
+          multi: true,
+        },
       ],
     }
   }