abort if digest could not be retreived

sync_kiwix.py

@@ -146,6 +146,8 @@ def download_wiki(session: requests.Session, title: str, src: str, dst: str):
         if method == "SHA-256":
             digest_value = base64.b64decode(data)
             break
+    else:
+        raise SystemExit(f"Could not get SHA-256 digest for {title}. Aborting.")
     
     sha256 = hashlib.sha256()
     with session.get(url=src, stream=True) as response:
@@ -194,7 +196,7 @@ def main():
         filelist = retreive_filelist(session=session, url=KIWIX_BASE_URL)
         save_cached_filelist(cache_file=args.cache_file, filelist=filelist)
 
-    # Get downlaod files list
+    # Get download files list
     download_files = get_download_files(wikis=args.wiki, filelist=filelist)
 
     # Download files