Use the correct path of InvalidConfiguration

Since I9ec697c61cfb1f5750d82ae790c607029bfed3ca, we have moved
InvalidConfiguration exception to tempest.lib. There are still
two file have not been changed, this patch is a supplement.

Change-Id: I15952fa9cc83b82aeca26f66f63e9c82ea554f7d
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index b738e82..d8294f7 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -365,7 +365,7 @@
                     return address['addr']
             raise exceptions.ServerUnreachable(server_id=server['id'])
         else:
-            raise exceptions.InvalidConfiguration()
+            raise lib_exc.InvalidConfiguration()
 
     def setUp(self):
         super(BaseV2ComputeTest, self).setUp()
diff --git a/tempest/api/compute/images/test_image_metadata.py b/tempest/api/compute/images/test_image_metadata.py
index 999233d..26d4efe 100644
--- a/tempest/api/compute/images/test_image_metadata.py
+++ b/tempest/api/compute/images/test_image_metadata.py
@@ -20,7 +20,7 @@
 from tempest.common.utils import data_utils
 from tempest.common import waiters
 from tempest import config
-from tempest import exceptions
+from tempest.lib import exceptions
 from tempest import test
 
 CONF = config.CONF