(fix): use .get() to avoid KeyError (#347)

Author: CyanVoxel

tagstudio/src/qt/modals/folders_to_tags.py

@@ -61,7 +61,7 @@ def add_folders_to_tree(items: list[str]) -> Tag:
                 library.add_tag_to_library(new_tag)
                 branch["dirs"][folder] = dict(dirs={}, tag=new_tag)
             branch = branch["dirs"][folder]
-        return branch["tag"]
+        return branch.get("tag")
 
     for tag in library.tags:
         reversed_tag = reverse_tag(library, tag, None)