chg: declare environ (issue6812) stable

chg: declare environ (issue6812)

--- a/contrib/chg/chg.c	Tue Apr 18 11:48:22 2023 +0200
+++ b/contrib/chg/chg.c	Mon Apr 24 10:30:08 2023 -0400
@@ -31,6 +31,8 @@
 #define PATH_MAX 4096
 #endif
 
+extern char **environ;
+
 struct cmdserveropts {
 	char sockname[PATH_MAX];
 	char initsockname[PATH_MAX];