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_server.h b/aos/network/sctp_server.h
index e641fd8..996645e 100644
--- a/aos/network/sctp_server.h
+++ b/aos/network/sctp_server.h
@@ -19,8 +19,7 @@
 #include "aos/network/sctp_lib.h"
 #include "aos/unique_malloc_ptr.h"
 
-namespace aos {
-namespace message_bridge {
+namespace aos::message_bridge {
 
 class SctpServer {
  public:
@@ -74,7 +73,6 @@
   SctpReadWrite sctp_;
 };
 
-}  // namespace message_bridge
-}  // namespace aos
+}  // namespace aos::message_bridge
 
 #endif  // AOS_NETWORK_SCTP_SERVER_H_