Merge pull request #4244 from overleaf/hb-fix-transparent-richtext-more

Put background colour on richtext toolbar "more"

GitOrigin-RevId: 5376bccdf701e0565553beb10405b2ff535d9468

services/web/frontend/stylesheets/core/ol-light-variables.less

@@ -115,7 +115,7 @@
 @formatting-btn-color: @toolbar-icon-btn-color;
 @formatting-btn-bg: transparent;
 @formatting-btn-border: @ol-blue-gray-1;
-@formatting-menu-bg: transparent;
+@formatting-menu-bg: #fff;
 
 // Chat
 @chat-bg: #fff;