Remove obsolete remark that PQprepare() is more flexible than PREPARE.

Spotted by Dmitriy Igrishin.  Back-patch to 8.2, which is when the PREPARE
statement was improved to allow parameter types to be omitted.

doc/src/sgml/libpq.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.321 2010/08/17 04:37:20 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.322 2010/08/29 15:19:05 tgl Exp $ -->
 
 <chapter id="libpq">
  <title><application>libpq</application> - C Library</title>
@@ -1895,9 +1895,7 @@ PGresult *PQprepare(PGconn *conn,
 
     Prepared statements for use with <function>PQexecPrepared</> can also
     be created by executing SQL <xref linkend="sql-prepare">
-    statements.  (But <function>PQprepare</>
-    is more flexible since it does not require parameter types to be
-    pre-specified.)  Also, although there is no <application>libpq</>
+    statements.  Also, although there is no <application>libpq</>
     function for deleting a prepared statement, the SQL <xref
     linkend="sql-deallocate"> statement
     can be used for that purpose.