Do not created uneeded folders.

Fix double trailing "/". Add sane defaults.

software/osie-coupler/buildout.hash.cfg

 [instance-profile]
 filename = instance.cfg.in
-md5sum = 6610ce91964dda42edbcb5b7837777c2
+md5sum = cf6c11bc335c75139695008128f1565a

software/osie-coupler/instance.cfg.in

 configuration.coupler_block_device = /dev/i2c-1
 configuration.coupler_i2c_slave_list = 0x58
 configuration.mode = 0
-configuration.username =
-configuration.password =
+configuration.username = ""
+configuration.password = ""
 configuration.interface = 0.0.0.0
 configuration.opc_ua_port = 4840
 configuration.id = 0
 configuration.heart_beat_id_list =
 configuration.network_address_url_data_type = opc.udp://224.0.0.22:4840/
 configuration.heart_beat_timeout_interval = 100
-configuration.network_interface =
+configuration.network_interface = ""
 
 [directory]
 recipe = slapos.cookbook:mkdirectory
 var = ${:home}/var
 script = ${:etc}/run/
 service = ${:etc}/service
-log = ${:var}/log
 
 [publish-connection-parameter]
 recipe = slapos.cookbook:publish

software/osie-coupler/software.cfg

 recipe  = slapos.recipe.build:gitclone
 git-executable = ${git:location}/bin/git
 repository = https://lab.nexedi.com/nexedi/osie.git
-revision = a40573897e1ee9de7b3536daa58c6904384c10f9
+revision = 5d193e57b50a7ebb3df147e403917201eb9cb6c6
 
 [compile-coupler]
 recipe = slapos.recipe.cmmi
-path = ${osie-repository:location}/coupler/
+path = ${osie-repository:location}/coupler
 bin_dir = ${:path}/bin/
 environment =
   OPEN62541_HOME = ${open62541:location}