patch 8.1.1567: localtime_r() does not respond to $TZ changes

Problem:    Localtime_r() does not respond to $TZ changes.
Solution:   If $TZ changes then call tzset(). (Tom Ryder)
diff --git a/src/auto/configure b/src/auto/configure
index c326abf..8dcad0b 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -12569,7 +12569,7 @@
 	memset mkdtemp nanosleep opendir putenv qsort readlink select setenv \
 	getpgid setpgid setsid sigaltstack sigstack sigset sigsetjmp sigaction \
 	sigprocmask sigvec strcasecmp strerror strftime stricmp strncasecmp \
-	strnicmp strpbrk strtol tgetent towlower towupper iswupper \
+	strnicmp strpbrk strtol tgetent towlower towupper iswupper tzset \
 	usleep utime utimes mblen ftruncate unsetenv posix_openpt
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`