recovered when using lbmethod_bybusyness.
PR: 48735
Markus Stoll and Adam C both submitted patches against 2.2.x
to bug 48735. Compared with those two, this solution
1. resets the busy field in the error-ed worker at the end of
the request instead of at recovery time
2. leaves the lbstatus field alone
3. covers all possible scenarios where the busy field in the
error-ed worker needs to be adjusted, since a cleanup to
perform the decrement is registered at the point of the
increment
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1366344 13f79535-47bb-0310-9956-ffa450edef68