tweak "requests currently being processed". It is confusing to not have

old generation requests included after a graceful restart.  But we
shouldn't count workers who are starting up.

OTOH, the "ready" counter needs to pay attention to the generation, so it
stays in sync with how p_i_s_m counts idle workers.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95272 13f79535-47bb-0310-9956-ffa450edef68