Get the ldconfig check to work for bash shells.

diff --git a/configure b/configure
index 8c8ddab..3b4402a 100755
--- a/configure
+++ b/configure
@@ -4130,7 +4130,7 @@
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in /sbin:/usr/sbin:$PATH
+for as_dir in /sbin /usr/sbin $PATH
 do
   IFS=$as_save_IFS
   test -z "$as_dir" && as_dir=.