docs - correct a gpexpand status value
<entry colname="col2">text</entry>
<entry colname="col3"/>
<entry colname="col4">Status of expansion for this table. Valid values are:<p>NOT
- STARTED</p><p>IN PROGRESS</p>FINISHED<p>NO LONGER EXISTS</p></entry>
+ STARTED</p><p>IN PROGRESS</p><p>COMPLETED</p><p>NO LONGER EXISTS</p></entry>
</row>
<row>
<entry colname="col1">
