Silence some warnings (#1488)

* Fix warning on startup

* Fix warning on rename

* Remove stray pasted text

---------

Co-authored-by: Jeremy Wootten <jeremy@Proteus-EL07R6-9b3c42bb.localdomain>
Co-authored-by: Ryan Kornheisl <ryan@skarva.tech>

Author: 3 people

src/MainWindow.vala

@@ -604,6 +604,7 @@ namespace Scratch {
                     title = _("%s - %s").printf (doc.get_basename (), base_title);
 
                     toolbar.set_document_focus (doc);
+
                     folder_manager_view.select_path (doc.file.get_path ());
 
                     // Must follow setting focus document for editorconfig plug

src/Widgets/SourceList/SourceList.vala

@@ -870,7 +870,11 @@ public class SourceList : Gtk.ScrolledWindow {
             return items.has_key (item);
         }
 
-        public void update_item (Item item) requires (has_item (item)) {
+        public void update_item (Item item) {
+            if (!has_item (item)) {
+                return;
+            }
+
             assert (root != null);
 
             // Emitting row_changed() for this item's row in the child model causes the filter