[rai] Fix typos

youtube_dl/extractor/rai.py

@@ -118,13 +118,13 @@ class RaiTVIE(InfoExtractor):
                 if ext == 'm3u8':
                     m3u8_formats = self._extract_m3u8_formats(
                         media_url, video_id, 'mp4', 'm3u8_native', m3u8_id='hls',
-                        fatal=None)
+                        fatal=False)
                     if m3u8_formats:
                         formats.extend(m3u8_formats)
                 elif ext == 'f4m':
                     f4m_formats = self._extract_f4m_formats(
                         media_url + '?hdcore=3.7.0&plugin=aasp-3.7.0.39.44',
-                        video_id, f4m_id='hds', fatal=None)
+                        video_id, f4m_id='hds', fatal=False)
                     if f4m_formats:
                         formats.extend(f4m_formats)
                 elif ext == 'stl':