Fix detection of libaceclnt for securid_sam2

The symbol we need is SD_Init(), not sd_init().

https://github.com/krb5/krb5/commit/081ee2f7d98b939bf7b4866845d4243b5ca3992c
Author: Greg Hudson <ghudson@mit.edu>
Commit: 081ee2f7d98b939bf7b4866845d4243b5ca3992c
Branch: master
 src/configure.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)