Fix proceeding filename

The basename in the RSS feed changed from 20138 on, from
NNNNN-data.xml to NNNNN.xml
Handle both situations

optv/parliaments/DE/scraper/fetch_proceedings.py

@@ -13,6 +13,7 @@
 import lxml.html
 import os
 from pathlib import Path
+import re
 import sys
 import urllib.request
 import urllib3
@@ -49,8 +50,13 @@ def download_plenary_protocols(destination_dir: str, fullscan: bool = False, per
             link_href = link.attrib["href"]
             link_count += 1
             basename = os.path.basename(link_href)
-            # Rename NNNN-data.xml to NNNN-proceedings.xml to be more clear
-            basename = basename.replace('-data.xml', '-proceedings.xml')
+            # Get session id from filename.
+            # The basename is either NNNNN-data.xml or NNNNN.xml (from 20138 on)
+            ids = re.findall(r'^(\d+)', basename)
+            if not ids:
+                raise ValueError(f"Invalid filename {basename} - cannot extract session id")
+            session_id = ids[0]
+            basename = f"{session_id}-proceedings.xml"
             filename = dest / basename
             if filename.exists():
                 # Existing file.