Remove personalization in new Xpass constant docs

Author: Girgias

reference/xpass/constants.xml

@@ -25,8 +25,8 @@
      because there are only <literal>4096</literal> possible salts and 2**56 distinct passphrases,
      which it truncates to 8 characters,
      it is feasible to discover any passphrase hashed with this method.
-     It should only be used if you absolutely have to generate hashes that will
-     work on an old operating system that supports nothing else.
+     It should only be used when supporting old operating systems that support
+     no other hash generation algorithm, due to how weak DES hashes are.
     </simpara>
    </listitem>
   </varlistentry>