Bugfix for adding words to a list

This commit fixes two bugs related to adding words to a list:
- When there is whitespace at the end of the words entered by the user, the words weren't added properly.
- When both the vocabId and the tradVocabId are sent to the server, both IDs must exist, otherwise the server will return an HTTP 400 error. The bugfix consists of only sending the vocabId ending in "-0" which should always exist. I tested it and it works for both traditional and simplified characters.