update changelog

CHANGELOG

@@ -2,7 +2,7 @@
 
 
 #### 2.4.0-alpha
-- support 2.4.0-alpha.1 agora video sdk android-2.4.0 / iOS-2.4.0.1 and add sendMessage support in the same channel.
+- support 2.4.0-alpha.1 agora video sdk android-2.4.0 / iOS-2.4.0.1 and add sendMessage support in the same channel. Deprecate: startEchoTest and setVideoQualityParameters
 
 #### 2.3.3-alpha
 - support agora video sdk 2.3.3