software/powerdns: use shorter path for socket

powerdns uses a socket named pdns.controlsocket in socket-dir (
https://doc.powerdns.com/authoritative/running.html#control-socket )
We sometimes see errors on test nodes that this path is too long:

     Aug 13 20:54:10 Unable to open controlsocket, path '/srv/slapgrid/slappart13/srv/testnode/cvr/inst/test0-0/tmp/inst/pdns1/var/run/pdns-socket/pdns.controlsocket' is not a valid UNIX socket path.

Instead of using "var/run/pdns-socket", put the socket in "var/run",
which should be short enough.

software/powerdns/buildout.hash.cfg

@@ -18,7 +18,7 @@ md5sum = fddea033e1aa9d6147a1a47bd7cc4b62
 
 [template-powerdns]
 filename = instance-powerdns.cfg
-md5sum = 2adb91323d60fc350f52910a3257d4a7
+md5sum = 9cd4e436fa432f37b9f8f4de8350581b
 
 [template-pdns-configuration]
 _update_hash_filename_ = template/pdns.conf.jinja2

software/powerdns/instance-powerdns.cfg

@@ -58,7 +58,7 @@ configuration = $${pdns-directory:configuration}/pdns.conf
 local-ipv4 = $${instance-parameter:ipv4-random}
 ipv6 = $${instance-parameter:ipv6-random}
 port = 5353
-socket-directory = $${pdns-directory:socket}
+socket-directory = $${pdns-directory:socket-directory}
 webserver-port = 8088
 
 [geo]
@@ -68,7 +68,7 @@ database = ${geolite2-country:location}/GeoLite2-Country.mmdb
 [pdns-directory]
 recipe = slapos.cookbook:mkdirectory
 configuration = $${directory:etc}/pdns
-socket = $${directory:run}/pdns-socket
+socket-directory = $${directory:run}/
 
 [pdns-configuration-template]
 < = jinja2-template-base