ethernet_interface: Remove unused resolvconf file

Change-Id: Ia3fdaa82c8d456569c1f0909bf9a7a42225523c9
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/ethernet_interface.hpp b/src/ethernet_interface.hpp
index a9b1bbd..8826ce8 100644
--- a/src/ethernet_interface.hpp
+++ b/src/ethernet_interface.hpp
@@ -233,8 +233,6 @@
 
     using EthernetInterfaceIntf::defaultGateway;
     using EthernetInterfaceIntf::defaultGateway6;
-    /** @brief Absolute path of the resolv conf file */
-    static constexpr auto resolvConfFile = "/etc/resolv.conf";
 
   protected:
     /** @brief get the info of the ethernet interface.