docs: update Stream logo with latest brand asset (#655)

Author: tyaga001

README.md

@@ -43,7 +43,7 @@
 <p align="center">
 <strong>Silver Sponsors:</strong><br>
 <a href="https://getstream.io/video/voice-calling/?utm_source=https://github.com/webrtc-rs/webrtc&utm_medium=sponsorship&utm_content=&utm_campaign=webrtcRepo_July2023_video_klmh22" target="_blank">
-<img src="https://stream-blog-v2.imgix.net/blog/wp-content/uploads/f7401112f41742c4e173c30d4f318cb8/stream_logo_white.png?h=50" alt="Stream Chat">
+<img src="https://raw.githubusercontent.com/webrtc-rs/webrtc/master/doc/stream-logo.png" height="50" alt="Stream Chat">
 </a><br>
 <a href="https://channel.io/" target="_blank">
 <img src="https://raw.githubusercontent.com/webrtc-rs/webrtc/master/doc/ChannelTalk_logo.png" alt="ChannelTalk">