Avoid an implicit declaration of utime in the configure script.  This
ensures that the package continues to build with future compilers
which do not support such implicit declarations by default.

This is a downstream-only patch.  Upstream, the configure file is
generated correctly since the following gnulib commit:

commit c20ba6929e5ac4a9cc72cd2b1f2d938e219adb01
Author: Bruno Haible <bruno@clisp.org>
Date:   Sat Jan 23 22:10:25 2021 +0100

    utime: Fix configure test (regression 2020-12-04).
    
    Reported by Ryan Schmidt <wget@ryandesign.com> via Tim Rühsen in
    <https://lists.gnu.org/archive/html/bug-gnulib/2021-01/msg00282.html>.
    
    * m4/utime.m4 (gl_FUNC_UTIME): In the test program, include <utime.h>,
    not <time.h>.

diff --git a/configure b/configure
index 129500e018d38aa5..7ed132239c78d2ac 100755
--- a/configure
+++ b/configure
@@ -36685,7 +36685,7 @@ else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 #include <stddef.h>
-                 #include <time.h>
+#include <utime.h>
 
 int
 main ()
diff --git a/m4/utime.m4 b/m4/utime.m4
index 03df7b7282500c73..bdff29d85982cd68 100644
--- a/m4/utime.m4
+++ b/m4/utime.m4
@@ -34,7 +34,7 @@ AC_DEFUN([gl_FUNC_UTIME],
            AC_RUN_IFELSE(
              [AC_LANG_PROGRAM(
                [[#include <stddef.h>
-                 #include <time.h>
+                 #include <utime.h>
                ]],
                [[int result = 0;
                  if (!utime ("conftest.tmp/", NULL))