PLT-7398 Removed flex-basis from search box (#7204)

webapp/sass/components/_search.scss

@@ -1,8 +1,6 @@
 @charset 'UTF-8';
 
 .search-bar__container {
-    @include flex(0 0 79px);
-
     .channel-header__links {
         .sidebar--right & {
             line-height: 25px;