patch 8.1.2326: cannot parse a date/time string

Problem:    Cannot parse a date/time string.
Solution:   Add strptime(). (Stephen Wall, closes #)
diff --git a/src/auto/configure b/src/auto/configure
index d591ab5..713bf9ea 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -12572,8 +12572,8 @@
 	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 tzset \
-	usleep utime utimes mblen ftruncate unsetenv posix_openpt
+	strnicmp strpbrk strptime 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" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"