apache: Allow more processes/connections as the same time

apache: Allow more processes/connections as the same time

In large networks, when ever multiple clients connect at the
same time and request the proxy.pac configuration file, apache
rate-limited requests so that some clients did not get a response
and therefore could not connect to the Internet.

This allows apache to handle more connections at the same time.

Suggested-by: Thoralf Söldenwagner <soeldenwagner@brecht-schule.hamburg>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>