Nest some more namespaces

Did someone previously suggest that all namespace had been
nested?  Silly.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I22278c1caaeba8b47dc46fb2ed3078c20a11e190
diff --git a/aos/network/sctp_client.h b/aos/network/sctp_client.h
index 9b9265e..952d0e9 100644
--- a/aos/network/sctp_client.h
+++ b/aos/network/sctp_client.h
@@ -11,8 +11,7 @@
 #include "aos/network/sctp_lib.h"
 #include "aos/unique_malloc_ptr.h"
 
-namespace aos {
-namespace message_bridge {
+namespace aos::message_bridge {
 
 // Class to encapsulate everything needed to be a SCTP client.
 class SctpClient {
@@ -73,7 +72,6 @@
   sctp_assoc_t sac_assoc_id_ = 0;
 };
 
-}  // namespace message_bridge
-}  // namespace aos
+}  // namespace aos::message_bridge
 
 #endif  //  AOS_NETWORK_SCTP_CLIENT_H_