Merge pull request #2597 from teamcapybara/set_cause_manually

Set the cause on the server error, unclear why it wasn't being auto-set

lib/capybara/session.rb

@@ -162,9 +162,8 @@ module Capybara
         if config.raise_server_errors
           raise CapybaraError, 'Your application server raised an error - It has been raised in your test code because Capybara.raise_server_errors == true'
         end
-      rescue CapybaraError
-        # needed to get the cause set correctly in JRuby -- otherwise we could just do raise @server.error
-        raise @server.error, @server.error.message, @server.error.backtrace
+      rescue CapybaraError => capy_error
+        raise @server.error, cause: capy_error
       ensure
         @server.reset_error!
       end