slaprunner: better way to list instance's backup files in export script

Getting them from the runner backup avoids to get false positive if some
of the instance's backup files were excluded using an exporter.exclude file

software/slaprunner/common.cfg

@@ -84,7 +84,7 @@ recipe = hexagonit.recipe.download
 ignore-existing = true
 url = ${:_profile_base_location_}/template/runner-export.sh.jinja2
 download-only = true
-md5sum = e2d472ade09c11c70dbea080932e80bd
+md5sum = 2e96b9daa5cd20fc77e9573a9ce3fe52
 filename = runner-export.sh.jinja2
 mode = 0644
 

software/slaprunner/template/runner-export.sh.jinja2

@@ -72,8 +72,9 @@ remove_tmp_files () {
 }
 trap remove_tmp_files EXIT
 
-cd $srv_directory
-
+# Getting files from runner backup directory, as instance backup files may be
+# explicitely excluded from the backup, using the srv/exporter.exclude
+cd {{ directory['backup'] }}
 backup_directory_path=$(find . -path "./runner/instance/slappart*/srv/backup/*" -type f)
 
 # If no backup found, it's over