Update NEWS for new release

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/8344)

NEWS

@@ -7,7 +7,10 @@
 
   Major changes between OpenSSL 1.1.1a and OpenSSL 1.1.1b [under development]
 
-      o
+      o Change the info callback signals for the start and end of a post-handshake
+        message exchange in TLSv1.3.
+      o Fix a bug in DTLS over SCTP. This breaks interoperability with older versions
+        of OpenSSL like OpenSSL 1.1.0 and OpenSSL 1.0.2.
 
   Major changes between OpenSSL 1.1.1 and OpenSSL 1.1.1a [20 Nov 2018]