Revert "Show an error page if the rest api is not available"

src/app/core/server-check/server-check.guard.ts

@@ -1,46 +0,0 @@
-import { Injectable } from '@angular/core';
-import { ActivatedRouteSnapshot, CanActivateChild, Router, RouterStateSnapshot } from '@angular/router';
-
-import { interval, Observable, race } from 'rxjs';
-import { map, mergeMapTo, tap } from 'rxjs/operators';
-
-import { RootDataService } from '../data/root-data.service';
-import { RemoteData } from '../data/remote-data';
-import { getPageInternalServerErrorRoute } from '../../app-routing-paths';
-import { getFirstCompletedRemoteData } from '../shared/operators';
-
-@Injectable({
-  providedIn: 'root'
-})
-/**
- * A guard that checks if root api endpoint is reachable.
- * If not redirect to 500 error page
- */
-export class ServerCheckGuard implements CanActivateChild {
-  constructor(private router: Router, private rootDataService: RootDataService) {
-  }
-
-  /**
-   * True when root api endpoint is reachable.
-   */
-  canActivateChild(
-    route: ActivatedRouteSnapshot,
-    state: RouterStateSnapshot): Observable<boolean> {
-
-    const uncachedCheck$ = this.rootDataService.findRoot(false);
-    // fallback observable used if the uncached one hangs and doesn't emit value
-    const cachedCheck$ = interval(200).pipe(mergeMapTo((this.rootDataService.findRoot())));
-
-    return race([uncachedCheck$, cachedCheck$]).pipe(
-      getFirstCompletedRemoteData(),
-      map((res: RemoteData<any>) => res.hasSucceeded),
-      tap((hasSucceeded: boolean) => {
-        if (!hasSucceeded) {
-          this.rootDataService.invalidateRootCache();
-          this.router.navigateByUrl(getPageInternalServerErrorRoute());
-        }
-      }),
-    );
-
-  }
-}