Proceed import with non-existent history file

import_md/hedgedoc_import.py

@@ -33,11 +33,19 @@ def import_into_hedgedoc(instance_url, session_id, export_folder, archive_file):
         f"Checking existence of archive file ({archive_file})")
     check_file_exists(archive_file)
     # get exported history map
-    with open(os.path.join(export_folder, "history.json")) as map_file:
+    history_json_filename = "history.json"
+    history_dictionary = {}
+    try:
+        with open(os.path.join(export_folder, "%s" % history_json_filename)) as map_file:
             history_dictionary = json.load(map_file)
+    except FileNotFoundError:
+        print_block_heading(
+            f"INFO: could not find file {history_json_filename}. Continuing anyways with random generated paths for "
+            f"documents")
 
     # mapping from title of a document (= filename without md extension in archive) to its id (= note url in CodiMD)
     lookup_map = {}
+    if "history" in history_dictionary:
         for entry in history_dictionary["history"]:
             lookup_map[entry["text"]] = entry["id"]