Problem: The Special:UrlShortener UI will not generate new short url's with out reloading, but looks like it will.

Steps to reproduce:

1. Goto https://meta.wikimedia.org/wiki/Special:UrlShortener
2. Enter a long URL, Click Shorten
3. Enter a new long URL, Click Shorten

RESULT: Nothing happens after step 3
EXPECTED RESULT: A shortURL will be generated for the long URL in step 3

Suggested options:
(A) Generate the expected result above instead of doing nothing
(B) Deactivate the input box after step 2, so that user won't think they can still make use of it at this time