Safer downloading

validation/validate-mmcif-file.py

@@ -226,7 +226,7 @@ def _download_file(file_url):
     """Download a file into a temporary file. Mark for deletion on
     termination"""
     rspns = requests.get(file_url, stream=True, timeout=600)
-    if rspns.status_code != 200:
+    if not rspns.ok:
         raise RuntimeError(f"File not found by URL '{file_url}'.")
 
     dlf = tempfile.TemporaryFile()