fix[sidebar.css]: remove redundant css

Author: PanJiaChen

src/styles/sidebar.scss

@@ -95,10 +95,6 @@
       margin-left: 54px;
     }
 
-    .svg-icon {
-      margin-right: 0px;
-    }
-
     .submenu-title-noDropdown {
       padding: 0 !important;
       position: relative;