Restore functionality breaks when using Greek letters (e.g. β) in window name

[xave]

Functionality works as expected normally.

Steps to Reproduce
If a window is named something like Workspace(β) upon restore after closing tmux, the tmux before the rename will be resurrected.

If a window is named Workspace(β) and the session is manually saved and restored, tmux-ressurrect will remove every save state with that character:

Removed path/to/.tmux/ressurect/tmux_resurrect_<datehash1>.txt
Removed path/to/.tmux/ressurect/tmux_resurrect_<datehash2>.txt
Removed path/to/.tmux/ressurect/tmux_resurrect_<datehash3>.txt
Removed path/to/.tmux/ressurect/tmux_resurrect_<datehash4>.txt

Expected behavior
tmux-ressurrect is able to handle such characters gracefully.

[xave]

An additional note: It seems that it only removes all the window names (restoring to default).