Sesam integration: add sesam bin directory to LD_LIBRARY_PATH

[abbbi]

• Type: Bug Fix

• Impact: Normal /

On some systems (for example centos6 and/or ubuntu) REAR backup with Backup type SESAM
fails during verify of the rootfs due to missing libraries:

/opt/sesam/bin/sesam/Crypto.Hash._SHA256.so requires additional libraries (fatal error)
libpython2.7.so.1.0 => not found
/opt/sesam/bin/sesam/cPickle.so requires additional libraries (fatal error)
libpython2.7.so.1.0 => not found
ERROR: ReaR recovery system in '/tmp/rear.LyKD3Rt2V4XgYs2/rootfs' not usable

these libraries are part of the Sesam client integration itself but unfortunately are not found
due to the sesam installation directory not beeing part of LD_LIBRARY_PATH.

For TSM an alike issue has already been fixed as TSM sets the LD_LIBRARY_PATH:

./usr/share/rear/prep/TSM/default/400_prep_tsm.sh:# Find gsk lib diriectory and add it to the TSM_LD_LIBRARY_PATH
./usr/share/rear/prep/TSM/default/400_prep_tsm.sh:      TSM_LD_LIBRARY_PATH=$TSM_LD_LIBRARY_PATH:$gsk_dir

This patch does the same for the sesam client, installation directory is used from the
configuration file and not hardcoded.

[jsmeix]

Now it looks perfectly clean, i.e.
#1810 (comment)
is now fixed.