Revert 1fbc30f1 because the

--enable-shared is about Plyton's configure, not ours.

doc/src/sgml/installation.sgml

@@ -234,7 +234,8 @@ su - postgres
      </para>
 
      <para>
-      On some
+      If you have problems, run <productname>Python</> 2.3 or later's
+      configure using the <literal>--enable-shared</> flag.  On some
       operating systems you don't have to build a shared library, but
       you will have to convince the <productname>PostgreSQL</> build
       system of this.  Consult the <filename>Makefile</filename> in