software/dream: fix npm/nodejs invocation

npm invokes node from $PATH, so make sure we have proper node version in
PATH.

software/dream/software.cfg

@@ -26,7 +26,7 @@ initialization =
 [npm_install]
 recipe = plone.recipe.command
 stop-on-error = true
-command = cd ${dream-repository.git:location} && PATH=${git:location}/bin/:$PATH ${nodejs:location}/bin/npm install .
+command = cd ${dream-repository.git:location} && PATH=${git:location}/bin/:${nodejs:location}/bin/:$PATH ${nodejs:location}/bin/npm install .
 update_command = ${:command}
 
 [versions]