Fix syntax error in RAISE calls (#2942)

PostgreSQL 9.5 doesn't tolerate them...

git-svn-id: http://svn.osgeo.org/postgis/branches/2.1@13010 b70326c6-7e19-0410-871a-916f4a2858ee
Note the PostgreSQL 9.5 support in the news

git-svn-id: http://svn.osgeo.org/postgis/branches/2.1@13011 b70326c6-7e19-0410-871a-916f4a2858ee