patch 9.0.0108: configure check for timer_create may give wrong error

Problem:    Configure check for timer_create may give wrong error.
Solution:   Give a warning instead of an error.
diff --git a/src/auto/configure b/src/auto/configure
index 1fd75e2..1883611 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -13044,7 +13044,8 @@
 else
 
 if test "$cross_compiling" = yes; then :
-  as_fn_error $? "cross-compiling: please set 'vim_cv_timer_create'" "$LINENO" 5
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: failed to build test program; if cross-compiling please set 'vim_cv_timer_create'" >&5
+$as_echo "$as_me: WARNING: failed to build test program; if cross-compiling please set 'vim_cv_timer_create'" >&2;}
 
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
@@ -13098,7 +13099,8 @@
 else
 
     if test "$cross_compiling" = yes; then :
-  as_fn_error $? "cross-compiling: please set 'vim_cv_timer_create_with_lrt'" "$LINENO" 5
+  { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: failed to build test program; if cross-compiling please set 'vim_cv_timer_create_with_lrt'" >&5
+$as_echo "$as_me: WARNING: failed to build test program; if cross-compiling please set 'vim_cv_timer_create_with_lrt'" >&2;}
 
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext