added allow multi download mode setting frontend implementation

src/app/main/main.component.html

@@ -50,7 +50,7 @@
                 </form>
                 <br/>
                 <mat-checkbox [disabled]="current_download" (change)="videoModeChanged($event)" [(ngModel)]="audioOnly" style="float: left; margin-top: -12px">Only Audio</mat-checkbox>
-                <mat-checkbox [disabled]="current_download" (change)="multiDownloadModeChanged($event)" [(ngModel)]="multiDownloadMode" style="float: right; margin-top: -12px">Multi-download mode</mat-checkbox>
+                <mat-checkbox *ngIf="allowMultiDownloadMode" [disabled]="current_download" (change)="multiDownloadModeChanged($event)" [(ngModel)]="multiDownloadMode" style="float: right; margin-top: -12px">Multi-download mode</mat-checkbox>
                 
             </div>
         </mat-card-content>

src/app/main/main.component.ts

@@ -57,6 +57,7 @@ export class MainComponent implements OnInit {
   fileManagerEnabled = false;
   allowQualitySelect = false;
   downloadOnlyMode = false;
+  allowMultiDownloadMode = false;
   baseStreamPath;
   audioFolderPath;
   videoFolderPath;
@@ -200,6 +201,7 @@ export class MainComponent implements OnInit {
       const backendUrl = result['YoutubeDLMaterial']['Host']['backendurl'];
       this.fileManagerEnabled = result['YoutubeDLMaterial']['Extra']['file_manager_enabled'];
       this.downloadOnlyMode = result['YoutubeDLMaterial']['Extra']['download_only_mode'];
+      this.allowMultiDownloadMode = result['YoutubeDLMaterial']['Extra']['allow_multi_download_mode'];
       this.baseStreamPath = result['YoutubeDLMaterial']['Downloader']['path-base'];
       this.audioFolderPath = result['YoutubeDLMaterial']['Downloader']['path-audio'];
       this.videoFolderPath = result['YoutubeDLMaterial']['Downloader']['path-video'];