misc: rename namespace jami to namespace dhtnet

Change-Id: I904ec8fa1f35dfdcf1aabd5f1ec8d95989ad0696
diff --git a/src/string_utils.cpp b/src/string_utils.cpp
index e3141ae..d970011 100644
--- a/src/string_utils.cpp
+++ b/src/string_utils.cpp
@@ -159,4 +159,4 @@
     return output;
 }
 
-} // namespace jami
+} // namespace dhtnet