Windows Installer removed as it isn't available anymore

Author: bjori

error.php

@@ -236,6 +236,8 @@
     'install.sambar'             => 'install.windows.sambar',
     'install.solaris'            => 'install.unix.solaris',
     'install.xitami'             => 'install.windows.xitami',
+    'install.windows.installer.msi' => 'install.windows',
+    'install.windows.installer'  => 'install.windows',
 
     // Internals docs where moved
     'zend'                       => 'internals2.ze1.zendapi',