[Issue #249] hot_standby breaks partial restore for PG < 12

Author: gsmolk

doc/pgprobackup.xml

@@ -1880,6 +1880,14 @@ pg_probackup restore -B <replaceable>backup_dir</replaceable> --instance <replac
           <literal>template1</literal> databases are always restored.
         </para>
       </note>
+      <note>
+        <para>
+          Due to how recovery works in PostgreSQL < 12 it is advisable to
+          disable <option>hot_standby</option> option, when running partial
+          restore of PostgreSQL cluster of version less than <option>12</option>.
+          Otherwise recovery may fail.
+        </para>
+      </note>
     </refsect3>
   </refsect2>
   <refsect2 id="pbk-performing-point-in-time-pitr-recovery">