Undo of the imported SVG file doesn't work

[MouriyanRajendran]

Steps to reproduce:
Import a SVG file in the svgEdit web client. - SVG is drawn on the canvas
Click undo - canvas will be cleared.
Save as SVG - SVG file is saved in the computer
SVG file had contained the imported SVG file details.
Import the finally saved SVG file and you will be able to see the same content which were undone.

Expected behavior:
After clicking undo, SVG content should be updated and save as SVG should not contain the content from the imported SVG file.

[cuixiping]

I cannot reproduce it now. Maybe it'a old version relative issue.