CSS Fixes.

- Remove max height for MUC heading, otherwise subject text can get cut off
- Fix offset in mobile due to the background image

src/plugins/chatview/styles/chat-head.scss

@@ -30,7 +30,6 @@
                 padding: 0.5rem 1rem 0.5rem 1rem;
                 text-overflow: ellipsis;
                 width: 100%;
-                max-height: 5em;
             }
 
             .chatbox-title {

src/shared/styles/background.scss

@@ -115,3 +115,11 @@
         }
     }
 }
+
+@include media-breakpoint-down(m) {
+    #conversejs-bg {
+        .converse-brand {
+            display: none;
+        }
+    }
+}