Reduce conversation bottom padding

Revert inadvertent visual change introduced with vertical flex styling
in 0569d4c.

// FREEBIE

stylesheets/_conversation.scss

@@ -17,7 +17,7 @@
 .conversation {
   background-color: #ffffff;
   margin: 10px;
-  padding: 20px;
+  padding: 20px 20px 10px;
   border-radius: 10px;
   height: calc(100% - 20px);
   border-radius: 10px;

stylesheets/manifest.css

@@ -597,7 +597,7 @@ input.search {
 .conversation {
   background-color: #ffffff;
   margin: 10px;
-  padding: 20px;
+  padding: 20px 20px 10px;
   border-radius: 10px;
   height: calc(100% - 20px);
   border-radius: 10px; }