Add quotes to backport field

Author: nurse

tool/redmine-backporter.rb

@@ -45,7 +45,7 @@ module Readline; end
 @query = {
   'f[]' => BACKPORT_CF_KEY,
   "op[#{BACKPORT_CF_KEY}]" => '~',
-  "v[#{BACKPORT_CF_KEY}][]" => "#{TARGET_VERSION}: REQUIRED",
+  "v[#{BACKPORT_CF_KEY}][]" => "\"#{TARGET_VERSION}: REQUIRED\"",
   'limit' => 40,
   'status_id' => STATUS_CLOSE,
   'sort' => 'updated_on'