Use default Previous Work Dir if there is none

When the folder where the working dir was is deleted
an Exception is thrown. In that case a new default
directory is defined.

Change-Id: Ic0b3eb63625fc6cf6e90e9a77891c9958b6a9aee
Signed-off-by: Dominik Fleischmann <dominik.fleischmann@canonical.com>
diff --git a/n2vc/k8s_juju_conn.py b/n2vc/k8s_juju_conn.py
index 1f9c896..b2ef079 100644
--- a/n2vc/k8s_juju_conn.py
+++ b/n2vc/k8s_juju_conn.py
@@ -335,8 +335,10 @@
                     in the package>
                 - <URL_where_to_fetch_juju_bundle>
             """
-
-            previous_workdir = os.getcwd()
+            try:
+                previous_workdir = os.getcwd()
+            except FileNotFoundError:
+                previous_workdir = "/app/storage"
 
             bundle = kdu_model
             if kdu_model.startswith("cs:"):