Do not embed paths to build-only depends (-I...SDL2-dev and friends)
into savefile lua comments.
--- a/src/savestruct_internal.c
+++ b/src/savestruct_internal.c
@@ -571,8 +571,8 @@ void save_game_data(struct auto_string *strout)
 	autostr_append(strout,
 		"SAVEGAME: %s %s %s;sizeof(tux_t)=%d;sizeof(enemy)=%d;sizeof(bullet)=%d\n",
 		SAVEGAME_VERSION, SAVEGAME_REVISION, VERSION, (int)sizeof(tux_t), (int)sizeof(enemy), (int)sizeof(bullet));
-	autostr_append(strout, "BUILD_CFLAGS: %s\n", BUILD_CFLAGS);
-	autostr_append(strout, "BUILD_LDFLAGS: %s\n", BUILD_LDFLAGS);
+	autostr_append(strout, "BUILD_CFLAGS: %s\n", "<hidden>");
+	autostr_append(strout, "BUILD_LDFLAGS: %s\n", "<hidden>");
 	autostr_append(strout, "VERSION: %s\n", freedroid_version);
 	autostr_append(strout, "--]]\n");