Remove redundant parentheses

Author: rhpvorderman

src/isal/isal_zlib.pyi

@@ -64,7 +64,7 @@ def compressobj(level: int = ISAL_DEFAULT_COMPRESSION,
                 zdict = None) -> Compress: ...
 def decompressobj(wbits: int = MAX_WBITS, zdict = None) -> Decompress: ...
 
-class _GzipReader():
+class _GzipReader:
     def __init__(self, fp: typing.BinaryIO, buffersize: int = 32 * 1024): ...
     def readinto(self, obj) -> int: ...
     def readable(self) -> bool: ...