[simple-scan] Display Searching for Scanner after pressing Start Again

[Bartosz <bkosiorek src gnome org>]

commit 9e2fa871e0dd9f8a490f6f4e4dde8947a8ca3da5
Author: Bartosz Kosiorek <gang65 poczta onet pl>
Date:   Sat Apr 11 00:27:47 2020 +0200

    Display Searching for Scanner after pressing Start Again

 src/app-window.vala | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/app-window.vala b/src/app-window.vala
index 1befc73..92ba992 100644
--- a/src/app-window.vala
+++ b/src/app-window.vala
@@ -793,9 +793,10 @@ public class AppWindow : Gtk.ApplicationWindow
             if (scanning)
                 stop_scan ();
 
-            clear_document ();
-            /* Refresh list of devices to detect network scanners */
+            have_devices = false;
+            /* Refresh list of devices to detect network scanners, and fix issues with disconnected scanners 
*/
             redetect ();
+            clear_document ();
         });
     }