Config read twice : in cgi & GraphOld

[snide]

As reported by Jani M. :

Currently, the configuration needs to be read twice : once by the CGI script, and the second
time in graph_startup(). The overhead of launching new FastCGI processes could be cut in half if
the config was loaded only once.

With large configs, the savings would be substantial.

I'm putting it at priority low, since fastcgi does a good job in preforking when needed.