Add strange linker hack to fix asio

CMakeLists.txt

@@ -22,6 +22,7 @@ set(headers
 
 set(sources
     src/espstrutils.cpp
+    src/linker_hacks.cpp
     src/schedulertask.cpp
     src/taskutils.cpp
 )

src/linker_hacks.cpp

@@ -0,0 +1,15 @@
+// I dont know why but without this hack here the linker
+// fails for asio and I could not fix it otherwise
+
+extern "C" char *lwip_if_indextoname(unsigned int ifindex, char *ifname);
+extern "C" unsigned int lwip_if_nametoindex(const char *ifname);
+
+extern "C" char *if_indextoname(unsigned int ifindex, char *ifname)
+{
+    return lwip_if_indextoname(ifindex, ifname);
+}
+
+extern "C" unsigned int if_nametoindex(const char *ifname)
+{
+    return lwip_if_nametoindex(ifname);
+}