[chronojump] Small check on editing a session from load window

[Xavier de Blas <xaviblas src gnome org>]

commit 6fa51c1c4f5bf3d2787204a1625ec8d43adb06dc
Author: Xavier de Blas <xaviblas gmail com>
Date:   Thu Mar 18 17:15:48 2021 +0100

    Small check on editing a session from load window

 src/gui/app1/session/loadAndImport.cs | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/src/gui/app1/session/loadAndImport.cs b/src/gui/app1/session/loadAndImport.cs
index 994d947b..a79b4946 100644
--- a/src/gui/app1/session/loadAndImport.cs
+++ b/src/gui/app1/session/loadAndImport.cs
@@ -674,6 +674,10 @@ public partial class ChronoJumpWindow
                 */
                Session s = SqliteSession.Select (app1s_selected);
 
+               //just care if for any reason the session cannot be found
+               if(s.UniqueID == -1)
+                       return;
+
                if(s.Name == Constants.SessionSimulatedName)
                        new DialogMessage(Constants.MessageTypes.INFO, Constants.SessionProtectedStr());
                else {