Fix PostGIS test results

Author: mkgrgis

expected/13.15/with_gis_support/postgis.out

@@ -5,6 +5,7 @@ CREATE SERVER sqlite_svr FOREIGN DATA WRAPPER sqlite_fdw
 OPTIONS (database '/tmp/sqlite_fdw_test/common.db');
 --Testcase 4:
 CREATE EXTENSION IF NOT EXISTS postgis;
+NOTICE:  extension "postgis" already exists, skipping
 --Testcase 5:
 CREATE EXTENSION postgis_raster;
 --Testcase 6:

expected/14.12/with_gis_support/postgis.out

@@ -5,6 +5,7 @@ CREATE SERVER sqlite_svr FOREIGN DATA WRAPPER sqlite_fdw
 OPTIONS (database '/tmp/sqlite_fdw_test/common.db');
 --Testcase 4:
 CREATE EXTENSION IF NOT EXISTS postgis;
+NOTICE:  extension "postgis" already exists, skipping
 --Testcase 5:
 CREATE EXTENSION postgis_raster;
 --Testcase 6:

expected/15.7/with_gis_support/postgis.out

@@ -5,6 +5,7 @@ CREATE SERVER sqlite_svr FOREIGN DATA WRAPPER sqlite_fdw
 OPTIONS (database '/tmp/sqlite_fdw_test/common.db');
 --Testcase 4:
 CREATE EXTENSION IF NOT EXISTS postgis;
+NOTICE:  extension "postgis" already exists, skipping
 --Testcase 5:
 CREATE EXTENSION postgis_raster;
 --Testcase 6:

expected/16.3/with_gis_support/postgis.out

@@ -5,6 +5,7 @@ CREATE SERVER sqlite_svr FOREIGN DATA WRAPPER sqlite_fdw
 OPTIONS (database '/tmp/sqlite_fdw_test/common.db');
 --Testcase 4:
 CREATE EXTENSION IF NOT EXISTS postgis;
+NOTICE:  extension "postgis" already exists, skipping
 --Testcase 5:
 CREATE EXTENSION postgis_raster;
 --Testcase 6:

expected/17.0/with_gis_support/postgis.out

@@ -5,6 +5,7 @@ CREATE SERVER sqlite_svr FOREIGN DATA WRAPPER sqlite_fdw
 OPTIONS (database '/tmp/sqlite_fdw_test/common.db');
 --Testcase 4:
 CREATE EXTENSION IF NOT EXISTS postgis;
+NOTICE:  extension "postgis" already exists, skipping
 --Testcase 5:
 CREATE EXTENSION postgis_raster;
 --Testcase 6: