gtk: Trim changelog descriptions

html2runes unconditionally adds newlines before/after elements. This
creates a large blank space in the UI if the last thing in the changelog
description is a list.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

gtk/src/changelog.rs

@@ -30,7 +30,7 @@ where
         let markdown = if entry.as_ref().is_empty() {
             fl!("changelog-unavailable")
         } else {
-            html2runes::markdown::convert_string(entry.as_ref())
+            html2runes::markdown::convert_string(entry.as_ref()).trim().to_string()
         };
 
         // NOTE: If we don't set a max width in chars, the label resizes its parent.