sdbusplus: remove deprecated variant_ns

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I32c6c42a5ccee52c7c7f1ba3ad4e64567f23f6fa
diff --git a/system_configuration.cpp b/system_configuration.cpp
index 4c5700e..be5fc91 100644
--- a/system_configuration.cpp
+++ b/system_configuration.cpp
@@ -86,7 +86,7 @@
         report<InternalFailure>();
         return "";
     }
-    return sdbusplus::message::variant_ns::get<std::string>(name);
+    return std::get<std::string>(name);
 }
 
 std::string SystemConfiguration::defaultGateway(std::string gateway)