Fixes #2007

In the plugins before_show the datastore_active flag in the resource
dict would not be set if the sql query generated an exception.  This had
implications with pg 8.4 where the flag was not present because of a
query failure, but it was checked for in tests.

Have set the default to false and just overwrite it if the query does
not explode and if it returns a result.

ckanext/datastore/plugin.py

@@ -273,6 +273,9 @@ def before_show(self, resource_dict):
                 action='dump', resource_id=resource_dict['id'])
 
         connection = None
+
+        resource_dict['datastore_active'] = False
+
         try:
             connection = self.read_engine.connect()
             result = connection.execute(
@@ -281,8 +284,6 @@ def before_show(self, resource_dict):
             ).fetchone()
             if result:
                 resource_dict['datastore_active'] = True
-            else:
-                resource_dict['datastore_active'] = False
         finally:
             if connection:
                 connection.close()