Fixed testing codes that were not compliant with search user by email signature.

library/persistence/store_mysql/tests/application.e

@@ -28,7 +28,9 @@ feature {NONE} -- Initialization
 			l_node := custom_node ("Content", "Summary", "Title")
 			storage.new_user (default_user)
 			storage.new_user (custom_user ("u2", "p2", "e2"))
-			l_node.set_author (storage.user_by_email (default_user.email))
+			if attached default_user.email as l_email then
+				l_node.set_author (storage.user_by_email (l_email))
+			end
 --			storage.new_node (l_node)
 --			if attached {CMS_NODE} storage.node_by_id (1) as ll_node then
 --				storage.update_node_title (2,ll_node.id, "New Title")

library/persistence/store_mysql/tests/users/user_test_set.e

@@ -63,7 +63,9 @@ feature -- Test routines
 		do
 			u := default_user
 			storage.new_user (u)
-			assert ("Not void",  attached storage.user_by_email (u.email))
+			if attached u.email as l_email then
+				assert ("Not void",  attached storage.user_by_email (l_email))
+			end
 			assert ("Not void",  attached storage.user_by_id (2))
 			assert ("Not void",  attached storage.user_by_id (2) as l_user and then l_user.id = 2 and then l_user.name ~ u.name)
 			assert ("Not void",  attached storage.user_by_name (u.name))