fix(NcAvatar): remove extra border around icons

Signed-off-by: Maksim Sukharev <antreesy.web@gmail.com>

Author: Antreesy

src/components/NcAvatar/NcAvatar.vue

@@ -938,7 +938,6 @@ export default {
 		width: 40%;
 		line-height: 1;
 		font-size: clamp(var(--font-size-small, 13px), 85%, var(--default-font-size));
-		border: 2px solid var(--color-main-background);
 		background-color: var(--color-main-background);
 		background-repeat: no-repeat;
 		background-size: 16px;