Update src/fourc_webviewer/fourc_webserver.py

Co-authored-by: Copilot <[email protected]>

Author: LaSi5002

src/fourc_webviewer/fourc_webserver.py

@@ -990,7 +990,7 @@ def click_delete_section_button(self, **kwargs):
 
         self.state.section_names = sections_names
         self.state.selected_main_section_name = cur_main
-        self.state.selected_section_name = new_subs[0]
+        self.state.selected_section_name = new_subs[0] if new_subs else ""
 
     @change("add_section")
     def change_add_section(self, **kwargs):