jstestnode: fix regression from introduction of Xvfb promise

${xvfb-instance:display} is used in in runTestSuite.in

software/jstestnode/buildout.hash.cfg

@@ -15,7 +15,7 @@
 
 [instance]
 filename = instance.cfg.in
-md5sum = 42e7d1825f5582fbe2c55977e5abc574
+md5sum = ab08e75c26d06d95674042d4a2934716
 
 [template-nginx-service]
 filename = template-nginx-service.sh.in

software/jstestnode/instance.cfg.in

@@ -53,19 +53,20 @@ recipe = slapos.cookbook:wrapper
 wrapper-path = $${directory:services}/$${:_buildout_section_name_}
 command-line =
   ${xserver:location}/bin/Xvfb
-    :$${:display}
+    $${:display}
     -screen 0 1024x768x24
     -fbdir $${directory:framebuffer}
 environment =
   XORG_LOCK_DIR=$${:lock-dir}
 
-display = 0
+display = :$${:display-number}
+display-number = 0
 lock-dir = $${directory:run}
 
 [xvfb-promise]
 recipe = slapos.cookbook:wrapper
 wrapper-path = $${directory:promise}/$${:_buildout_section_name_}
-command-line = bash -c "[ -S $${xvfb-instance:lock-dir}/.X11-unix/X$${xvfb-instance:display} ]"
+command-line = bash -c "[ -S $${xvfb-instance:lock-dir}/.X11-unix/X$${xvfb-instance:display-number} ]"
 
 
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