Switch to fully supported C++17

src/Object.cpp

@@ -37,7 +37,7 @@
 #include <utility>
 #include <cassert>
 
-namespace sdbus { namespace internal {
+namespace sdbus::internal {
 
 Object::Object(sdbus::internal::IConnection& connection, std::string objectPath)
     : connection_(connection), objectPath_(std::move(objectPath))
@@ -391,7 +391,7 @@ int Object::sdbus_property_set_callback( sd_bus */*bus*/
     return 1;
 }
 
-}}
+}
 
 namespace sdbus {