[PATCH] sslcrtvalidator_children concurrency option default value

Hi all,

currently we have the following situation for sslcrtvalidator_children
configuration option, which is may confusing people:
 1) The testing sslcrtvalidator helper supports concurrency
 2) The default concurrency if the sslcrtvalidator_children is not set,
is concurrency=0
 3) The default sslcrtvalidator_children line includes concurrency=1
 4) The documentation says:
     "Defaults to 0 which indicates the certficate validator
      is a old-style single threaded redirector."

This is make a confusion.

I am attaching a simple patch which set the concurrency option for
sslcrtvalidator_children by default to 1. I believe that this is the
best because the testing helper we provide supports concurrency by default.

Other options is
   a) set sslcrtvalidator_children default line to use concurrency=0
   b) Make a better documentation of the current behaviour to cf.data.pre

Opinions?