Bug: title disappears if your tag is rejected. [patch]

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Bug: title disappears if your tag is rejected.

If one of your tags fails the "use-these-chars-in-tags" check, the title of your question gets erased.

1) Ask question
2) Write a title
3) Put "&" or "%" in a tag name
4) Submit, observe error    "use-these-chars-in-tags".
5) Observe    title is now blank

(I used preformatted text, because on Chrome, number and bullet lists are broken)