exchange guest icon

src/app/components/shared/room-list/room-list.component.html

@@ -55,7 +55,7 @@
             </mat-icon>
             <mat-icon mat-list-icon *ngSwitchCase="participantRole"
                       title="{{ 'room-list.participant-role' | translate }}">
-              face
+              people
             </mat-icon>
             <mat-icon mat-list-icon *ngSwitchCase="executiveModeratorRole"
                       title="{{ 'room-list.executive-moderator-role' | translate }}">