Removed imports, that are not used.

src/Web/WebSPA/Client/modules/shared/services/configuration.service.ts

@@ -1,9 +1,9 @@
 import { Injectable } from '@angular/core';
-import { HttpClient, HttpHeaders, HttpErrorResponse } from "@angular/common/http";
+import { HttpClient } from "@angular/common/http";
 import { IConfiguration }   from '../models/configuration.model';
 import { StorageService }   from './storage.service';
 
-import { Observable, Subject } from 'rxjs';
+import { Subject } from 'rxjs';
 
 @Injectable()
 export class ConfigurationService {

src/Web/WebSPA/Client/modules/shared/services/data.service.ts

@@ -1,5 +1,5 @@
 import { Injectable } from '@angular/core';
-import { HttpClient, HttpHeaders, HttpErrorResponse } from "@angular/common/http";
+import { HttpClient, HttpHeaders } from "@angular/common/http";
 
 import { Observable, throwError } from 'rxjs';
 import { catchError, tap } from 'rxjs/operators';