CI: set a contact email for CI tests

Because this is used in some places, such as tor configuration, it can be useful
to have this set to something real for contact purposes.

tests/platform-ci/provider/provider.json

@@ -10,7 +10,7 @@
     "en": "You really should change this text"
   },
   "contacts": {
-    "default": "root@example.org"
+    "default": "sysdevs@leap.se"
   },
   "languages": ["en"],
   "default_language": "en",