get ab to compile on OS/390 by using strchr() instead of index()

get ab to compile on OS/390 by using strchr() instead of index()
(we could instead have included the proper header, but this is
the way Dirk fixed it in 2.0 since we already use strchr() and
thus had the proper header everywhere)

Get rid of incorrect code to save (and then ignore) the retval
from signal().  "void *" isn't compatible with any sort of
function pointer.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@89073 13f79535-47bb-0310-9956-ffa450edef68