FIX: correctly computes channels max height in float panel (#510)

FIX: correctly computes channels max height in float panel (#510)

diff --git a/assets/stylesheets/common/common.scss b/assets/stylesheets/common/common.scss
index 0d007ed..81c1d8c 100644
--- a/assets/stylesheets/common/common.scss
+++ b/assets/stylesheets/common/common.scss
@@ -237,7 +237,7 @@ body.composer-open .topic-chat-float-container {
 
 .topic-chat-drawer-content {
   box-sizing: border-box;
-  height: 100%;
+  height: calc(100% - #{$header-height});
   padding-bottom: 0.25em;
 
   .chat-channels .chat-channel-divider {

GitHub sha: 5ec67c5e03f3bccc20d1f3928eb701cd1ad2b999

This commit appears in #510 which was approved by davidtaylorhq. It was merged by jjaffeux.