[dreamwidth/dw-free] d0ba70: Fix issue with generating many captchas

[github]

Branch: refs/heads/develop
Home: https://github.com/dreamwidth/dw-free
Commit: d0ba70435993269ec02dd15340503d5569e15dd0
https://github.com/dreamwidth/dw-free/commit/d0ba70435993269ec02dd15340503d5569e15dd0
Author: Mark Smith <mark@qq.is>
Date: 2015-08-29 (Sat, 29 Aug 2015)

Changed paths:
M bin/maint/captcha.pl

Log Message:
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Fix issue with generating many captchas

There was a problem where if we generated N>many captchas, the DB would timeout. Instead we now flush them 10 by 10 as we get them, which also makes them available earlier.