[PostGIS] #5860: Improve CreateTopology error message when topology already exists

[PostGIS]

#5860: Improve CreateTopology error message when topology already exists
--------------------------+---------------------------
  Reporter:  strk         |      Owner:  strk
      Type:  enhancement  |     Status:  new
  Priority:  medium       |  Milestone:  PostGIS 3.6.0
 Component:  topology     |    Version:  3.4.x
Resolution:               |   Keywords:
--------------------------+---------------------------
Changes (by robe):

 * milestone:  PostGIS 3.5.3 => PostGIS 3.6.0

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5860#comment:1>
PostGIS <http://trac.osgeo.org/postgis/>
The PostGIS Trac is used for bug, enhancement & task tracking, a user and developer wiki, and a view into the subversion code repository of PostGIS project.