use correct read mode

Author: briangow

wfdb/io/record.py

@@ -1832,7 +1832,7 @@ def rdheader(record_name, pn_dir=None, rd_segments=False):
 
     # If this is a cloud path, use posixpath to construct the path
     if any(dir_name.startswith(proto) for proto in CLOUD_PROTOCOLS):
-        with fsspec.open(posixpath.join(dir_name, file_name), mode="rb") as f:
+        with fsspec.open(posixpath.join(dir_name, file_name), mode="r") as f:
             header_content = f.read()
 
     # If it isn't a cloud path, construct the download path using the database version