Only modify report_on_exception if the method is available

lib/vagrant/util/checkpoint_client.rb

@@ -75,7 +75,9 @@ module Vagrant
           logger.debug("starting plugin check")
           @checkpoint_thread = Thread.new do
             Thread.current.abort_on_exception = false
+            if Thread.current.respond_to?(:report_on_exception=)
               Thread.current.report_on_exception = false
+            end
             begin
               Thread.current[:result] = Checkpoint.check(
                 product: "vagrant",