Update changelog with server announcement

Author: saradickinson

ChangeLog

@@ -1,4 +1,7 @@
 *2020- : Version 0.4.0
+  * We announce the intention to remove the dnsovertls*.sinodun.com 
+    servers from the default resolver list in the next release,
+    see https://github.com/getdnsapi/stubby/issues/286 for details.
   * Add ability to run Stubby as a full Windows service
   * Update IPs for dot1.applied-privacy.net
   * Remove the secure.eu entries in the stubby config file