Update font size of chat input to match the text display in the chat area

bigbluebutton-html5/imports/ui/components/chat/message-list/message-list-item/styles.scss

 @import "/imports/ui/stylesheets/variables/_all";
 
 .item {
-  font-size: $font-size-base * .90;
+  font-size: $font-size-base;
   margin-bottom: $line-height-computed;
 
   &:last-child {

bigbluebutton-html5/imports/ui/stylesheets/variables/typography.scss

@@ -4,7 +4,7 @@ $font-family-monospace:   Menlo, Monaco, Consolas, "Courier New", monospace !def
 
 $font-family-base:        $font-family-sans-serif !default;
 
-$font-size-base:          1rem !default;
+$font-size-base:          0.9rem !default;
 $font-size-large:         1.25rem !default;
 $font-size-small:         .875rem !default;