fix esc key when finder not visible

Author: jonian

devdocs_desktop.py

@@ -148,7 +148,7 @@ def on_window_main_key_release_event(self, _widget, event):
     kname  = Gdk.keyval_name(event.keyval)
     text   = self.header_search.get_text()
     search = self.header_search.get_visible()
-    finder = self.finder_search.get_visible()
+    finder = self.revealer.get_reveal_child()
 
     if kname == 'Escape' and finder:
       self.revealer.set_reveal_child(False)