Fix none getattempt lambda

fix-none-getattempt-lambda is a cherry pick from #716, that fixes:
- a bug from #838 (see https://github.com/fail2ban/fail2ban/issues/838#issuecomment-60904420)
- a fix for disturbing "bug" within servertestcase - preventing to write into stderr (see https://github.com/fail2ban/fail2ban/pull/716#discussion-diff-14126349)
<blockquote>this fix alone may resolve the issue</blockquote>
Theoretical, but I don't think so:
- the "caching" of merged info does not take place or cleared (too many bans) - it will read twice (2x2);
- my solution is more safe - if tomorrow any other error occurred (database error, something else) - the ban/unban will be executed nevertheless (only other following actions will miss a merged info);
- in my solution (ban-time-incr) a writing of ban to database is completely asynchronous, so it will be even worse;