Added Apache::Version module as mod_pagespeed dependency

Added Apache::Version module as mod_pagespeed dependency, otherwise easyapache will fail and you may get error like this 

!! Failed to generate a syntactically correct Apache configuration (/usr/local/apache/conf/httpd.conf.1380522903):
Configuration problem detected on line 42 of file /usr/local/apache/conf/httpd.conf.1380522903: : Syntax error on line 2 of /usr/local/apache/conf/pagespeed.conf: Cannot load modules/mod_version.so into server: /usr/local/apache/modules/mod_version.so: cannot open shared object file: No such file or directory
        --- /usr/local/apache/conf/httpd.conf.1380522903 ---