Fix composer padding (#9137)

Author: weeman1337

res/css/structures/_RoomView.pcss

@@ -32,13 +32,6 @@ limitations under the License.
     position: relative;
 }
 
-.mx_MainSplit_timeline,
-.mx_RoomView--local {
-    .mx_MessageComposer_wrapper {
-        margin: $spacing-8 $spacing-16;
-    }
-}
-
 .mx_RoomView_auxPanel {
     min-width: 0px;
     width: 100%;