Merge pull request #1030 from Nakomis/postgresql-disconnect-on-stop

Removed .failOnNonZeroResultCode(), following review from ahgittin
diff --git a/software/database/src/main/java/brooklyn/entity/database/postgresql/PostgreSqlSshDriver.java b/software/database/src/main/java/brooklyn/entity/database/postgresql/PostgreSqlSshDriver.java
index 7c3f8b8..55bed4b 100644
--- a/software/database/src/main/java/brooklyn/entity/database/postgresql/PostgreSqlSshDriver.java
+++ b/software/database/src/main/java/brooklyn/entity/database/postgresql/PostgreSqlSshDriver.java
@@ -171,7 +171,7 @@
     public void stop() {
         newScript(MutableMap.of("usePidFile", false), STOPPING).body.append(callPgctl(
                 (entity.getConfig(PostgreSqlNode.DISCONNECT_ON_STOP) ? "-m immediate " : "") +
-                "stop", false)).failOnNonZeroResultCode().execute();
+                "stop", false)).execute();
     }
 
     @Override