Try to open tunX instead of glorytun by default in Linux

src/main.c

@@ -687,15 +687,10 @@ int main (int argc, char **argv)
 
     char *host = NULL;
     char *port = "5000";
+    char *dev = NULL;
     char *keyfile = NULL;
     char *congestion = NULL;
 
-#ifdef __linux__
-    char *dev = PACKAGE_NAME;
-#else
-    char *dev = NULL;
-#endif
-
     long buffer_size = GT_BUFFER_SIZE;
 
     long ka_count = -1;