Fix class name

Author: stanislavgeorgiev

src/ui-shell/sidenav/sidenav-item.component.ts

@@ -24,7 +24,7 @@ import { Router } from "@angular/router";
 				class="bx--side-nav__link"
 				[href]="href"
 				[ngClass]="{
-					'.bx--side-nav__link--current': active
+					'bx--side-nav__link--current': active
 				}"
 				[attr.role]="(isSubMenu ? 'menuitem' : null)"
 				[attr.aria-current]="(active ? 'page' : null)"