set open_ssl_port to false instead of nil for unit test shared examples

Author: chambersmp

spec/support/unit/shared/server.rb

@@ -6,7 +6,7 @@
       http_port: '8080',
       open_http_port: false,
       ssl_port: '8081',
-      open_ssl_port: nil,
+      open_ssl_port: false,
     }
   end