vty: Make the argument const
diff --git a/openbsc/include/vty/command.h b/openbsc/include/vty/command.h
index 21fb6a1..9daa2d6 100644
--- a/openbsc/include/vty/command.h
+++ b/openbsc/include/vty/command.h
@@ -351,7 +351,7 @@
 extern struct cmd_element config_help_cmd;
 extern struct cmd_element config_list_cmd;
 char *host_config_file();
-void host_config_set(char *);
+void host_config_set(const char *);
 
 void print_version(const char *);