Tune apache connections for tls proxy

We are seeing connection errors to the proxy occasionally. These errors
do not result in a logged http request or error to the backends,
resulting in a theory that the proxy itself may just not be able to
handle the number of connections. More than double the total number of
connections that will be accepted by the proxy in an attempt to fix
this.

Change-Id: Iefa6c43451dd1f95927528d2ce0003c84248847f
Related-bug: 1630664

lib/apache

@@ -29,15 +29,20 @@ APACHE_GROUP=${APACHE_GROUP:-$(id -gn $APACHE_USER)}
 
 
 # Set up apache name and configuration directory
+# Note that APACHE_CONF_DIR is really more accurately apache's vhost
+# configuration dir but we can't just change this because public interfaces.
 if is_ubuntu; then
     APACHE_NAME=apache2
     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/sites-available}
+    APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf-enabled}
 elif is_fedora; then
     APACHE_NAME=httpd
     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/conf.d}
+    APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf.d}
 elif is_suse; then
     APACHE_NAME=apache2
     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/vhosts.d}
+    APACHE_SETTINGS_DIR=${APACHE_SETTINGS_DIR:-/etc/$APACHE_NAME/conf.d}
 fi
 APACHE_LOG_DIR="/var/log/${APACHE_NAME}"