[chronojump] Fixed: DeleteAllStuff deletes forceSensor and runEncoder since last commits

[Xavier de Blas <xaviblas src gnome org>]

commit 65156a578f7f08f24695c75836a8768613797063
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Jun 30 07:57:32 2020 +0200

    Fixed: DeleteAllStuff deletes forceSensor and runEncoder since last commits

 src/sqlite/session.cs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/src/sqlite/session.cs b/src/sqlite/session.cs
index 6cb68d96..cf4b0d4d 100644
--- a/src/sqlite/session.cs
+++ b/src/sqlite/session.cs
@@ -1047,8 +1047,9 @@ class SqliteSession : Sqlite
                        folderSession = new System.IO.DirectoryInfo(
                                        Util.GetForceSensorSessionDir(Convert.ToInt32(sessionID)));
 
-                       foreach (FileInfo file in folderSession.GetFiles())
-                               Util.FileDelete(file.Name);
+                       if(folderSession.Exists)
+                               foreach (FileInfo file in folderSession.GetFiles())
+                                       Util.FileDelete(file.Name);
                }
 
                // delete runEncoder
@@ -1061,8 +1062,9 @@ class SqliteSession : Sqlite
                        folderSession = new System.IO.DirectoryInfo(
                                        Util.GetRunEncoderSessionDir(Convert.ToInt32(sessionID)));
 
-                       foreach (FileInfo file in folderSession.GetFiles())
-                               Util.FileDelete(file.Name);
+                       if(folderSession.Exists)
+                               foreach (FileInfo file in folderSession.GetFiles())
+                                       Util.FileDelete(file.Name);
                }
 
                //TODO: delete multimedia stuff of persons that have to be deleted, eg. on export: persons 
that are not in session (just for privacity)