Non-greedy matching for votestrings.

Non-greedy matching for votestrings.

A single choice on a ballot has this format:

 #1   [            ]  This or that

The regexp in uvvote.pl's process_vote() will
match and extract what's beetwen "[" and "]".
But if "This or that" contains a "]", the
match will be too greedy:

 #1   [            ]  This [or that]
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ <- match

Fix that by using a non-greedy operator.

Signed-off-by: Thomas Hochstein <thh@thh.name>