Update pam to version 1.5.2 / rev 126 via SR 1045205
    
    https://build.opensuse.org/request/show/1045205
    by user dimstar_suse
    - Also obsolete pam_unix-32bit to have clean upgrade path.
    
    - Merge pam_unix back into pam, seperate package not needed anymore
    
    - Update pam-git.diff to current upstream
      - pam_env: Use vendor specific pam_env.conf and environment as fallback
      - pam_shells: Use the vendor directory
      obsoletes pam_env_econf.patch
    - Refresh docbook5.patch