Revert "Store full location to xtrabackup_51_binary."

This reverts commit d64008dd.

Unfortunately innobackupex manual page lied about possibility to pass
directly path of backup agent, so it is required to rely on PATH
manipulation.

slapos/instance.cfg

@@ -28,7 +28,6 @@ runzeo_binary = ${buildout:bin-directory}/runzeo
 runzope_binary = ${buildout:bin-directory}/runzope
 tidstorage_repozo_binary = ${buildout:bin-directory}/tidstorage_repozo
 tidstoraged_binary = ${buildout:bin-directory}/tidstoraged
-xtrabackup_51_binary = ${xtrabackup:location}/bin/xtrabackup_51
 zabbix_agent_binary = ${zabbix-agent:location}/sbin/zabbix_agent
 
 # cloudooo specific configuration
@@ -46,6 +45,7 @@ link_binary_list =
   ${w3m:location}/bin/w3m
   ${xpdf:location}/bin/pdfinfo
   ${xpdf:location}/bin/pdftotext
+  ${xtrabackup:location}/bin/xtrabackup_51
 
 # XXX: products won't be needed as soon as all ERP5 (and products-deps)
 # products will be eggified so then it will be possible to use them thanks to

slapos/software.cfg

@@ -126,7 +126,7 @@ section = python2.7
 # Default template for erp5 instance.
 recipe = slapos.recipe.template
 url = ${:_profile_base_location_}/instance.cfg
-md5sum = 494fd0955b55bcd2e4ef94293083e90e
+md5sum = e728ad0200c3e78546549ac95cf41ced
 output = ${buildout:directory}/template.cfg
 mode = 0644