Fix connection tuning on >= trusty

The tuning config file needs a .conf extension.  Also, trusty
uses mpm_worker_event by default, so support that as well.

Change-Id: Ica3a7ceab29f120a24ca93cc5491f5fe8ce9e54a

files/apache-connection-tuning

@@ -27,3 +27,13 @@
     MaxClients         2048
     MaxRequestsPerChild   0
 </IfModule>
+<IfModule mpm_worker_event>
+    ServerLimit          64
+    StartServers          3
+    MinSpareThreads      96
+    MaxSpareThreads     192
+    ThreadLimit          64
+    ThreadsPerChild      32
+    MaxClients         2048
+    MaxRequestsPerChild   0
+</IfModule>

manifests/apache.pp

@@ -44,7 +44,7 @@ class etherpad_lite::apache (
       notify => Service['httpd'],
     }
   } else {
-    file { '/etc/apache2/conf-available/connection-tuning':
+    file { '/etc/apache2/conf-available/connection-tuning.conf':
       ensure => present,
       owner  => 'root',
       group  => 'root',
@@ -52,11 +52,11 @@ class etherpad_lite::apache (
       source => 'puppet:///modules/etherpad_lite/apache-connection-tuning',
     }
 
-    file { '/etc/apache2/conf-enabled/connection-tuning':
+    file { '/etc/apache2/conf-enabled/connection-tuning.conf':
       ensure  => link,
-      target  => '/etc/apache2/conf-available/connection-tuning',
+      target  => '/etc/apache2/conf-available/connection-tuning.conf',
       notify  => Service['httpd'],
-      require => File['/etc/apache2/conf-available/connection-tuning'],
+      require => File['/etc/apache2/conf-available/connection-tuning.conf'],
     }
 
     httpd_mod { 'proxy_wstunnel':