The note you trashed will be in the 'Trash' memoboard of the Notezilla
Notes Browser. Right-click on the Notezilla
icon and choose the 'Notes Browser' option and you will find it there.
Just move the note from the Trash memoboard to any other memoboard.
You can right click on that note and choose 'Stick to memoboard' and select another memoboard.