migrate to dhtnet namespace

Change-Id: I7143a010bd83e8cfa7a3c8c3072ed23f6f0ba8e3
diff --git a/src/peer_connection.h b/src/peer_connection.h
index 3798f0c..484562a 100644
--- a/src/peer_connection.h
+++ b/src/peer_connection.h
@@ -43,7 +43,7 @@
 } // namespace crypto
 } // namespace dht
 
-namespace jami {
+namespace dhtnet {
 namespace tls {
 class DhParams;
 }