Allow the build to succeed even if <productname>PostgreSQL</>

has no support for strong random numbers on the platform.

A source of random numbers is needed for some authentication

protocols, as well as some routines in <xref linkend="pgcrypto">

protocols, as well as some routines in the

<![%standalone-include[pgcrypto]]>

<![%standalone-ignore[<xref linkend="pgcrypto">]]>

module. --disable-strong-random disables functionality that

requires cryptographically strong random numbers, and substitutes

a weak pseudo-random-number-generator for the generation of