Fix unneeded top margin in Files sidebar chat

This reverts commit 81d76dde09.

The changes were needed due to the chat view having an absolute
position. Since Talk 12 that is no longer the case, so these changes
just caused an unneeded margin.

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

src/FilesSidebarTabApp.vue

@@ -39,9 +39,7 @@
 			</button>
 		</div>
 		<template v-else>
-			<div class="call-button-wrapper">
-				<CallButton class="call-button" />
-			</div>
+			<CallButton class="call-button" />
 			<ChatView />
 			<UploadEditor />
 		</template>
@@ -421,15 +419,7 @@ export default {
 	justify-content: center;
 }
 
-.call-button-wrapper {
-	width: 100%;
-	background-color: var(--color-main-background);
-	z-index: 1;
-}
-
 .call-button {
-	display: block;
-
 	/* Center button horizontally. */
 	margin-left: auto;
 	margin-right: auto;
@@ -438,10 +428,6 @@ export default {
 	margin-bottom: 10px;
 }
 
-::v-deep .scroller {
-	margin-top: 64px;
-}
-
 .chatView {
 	overflow: hidden;
 }