Development: Remove unused import in client file

src/main/webapp/app/exercises/shared/exercise-hint/manage/exercise-hint.route.ts

@@ -2,7 +2,7 @@ import { Injectable } from '@angular/core';
 import { HttpResponse } from '@angular/common/http';
 import { ActivatedRouteSnapshot, Resolve, Routes } from '@angular/router';
 import { UserRouteAccessService } from 'app/core/auth/user-route-access-service';
-import { Observable, of } from 'rxjs';
+import { of } from 'rxjs';
 import { filter, map } from 'rxjs/operators';
 import { ExerciseHintService } from './exercise-hint.service';
 import { ExerciseHintComponent } from './exercise-hint.component';