software/beremiz-runtime: fix compilation

The SR didn't compile without libssl-dev package. Correctly use the
openssl lib from slapos.

software/beremiz-runtime/software.cfg

@@ -6,6 +6,7 @@ extends =
   ../../component/open62541/buildout.cfg
   ../../component/numpy/buildout.cfg
   ../../component/lxml-python/buildout.cfg
+  ../../component/python-sslpsk/buildout.cfg
   ../../stack/monitor/buildout.cfg
   ../../stack/slapos.cfg
 
@@ -78,7 +79,7 @@ eggs = click
        opcua
        ${beremiz:egg}
        ${Twisted:egg}
-       sslpsk
+       ${python-sslpsk:egg}
 
 [instance-profile]
 recipe = slapos.recipe.template:jinja2