tools: Add missing openssl dependency to Debian's cockpit-ws package

This fixes the root cause for `remotectl certificate --ensure` not
working on Debian in issue cockpit-project#8690.

The RPM spec already has this dependency.

Author: martinpitt

tools/debian/control

@@ -180,6 +180,7 @@ Depends: ${misc:Depends},
          ${shlibs:Depends},
          glib-networking,
          adduser,
+         openssl,
 Conflicts: ${ws:Conflicts}
 Description: Cockpit Web Service
  The Cockpit Web Service listens on the network, and authenticates