playbook: Avoid exception during assertion

headers['Location'] might not exists, so get it with fallback to
nothing.

playbook/roles/standalone-shared/tests/testSiteHttp.py

@@ -22,7 +22,7 @@ class TestSiteHttp(unittest.TestCase):
         is_redirect=result.is_redirect,
         is_permanent_redirect=result.is_permanent_redirect,
         status_code=result.status_code,
-        location=result.headers['Location']
+        location=result.headers.get('Location')
       ),
       dict(
         ok=True,
@@ -45,7 +45,7 @@ class TestSiteHttp(unittest.TestCase):
         is_redirect=result.is_redirect,
         is_permanent_redirect=result.is_permanent_redirect,
         status_code=result.status_code,
-        location=result.headers['Location']
+        location=result.headers.get('Location')
       ),
       dict(
         ok=True,

playbook/roles/standalone-shared/tests/testSiteHttps.py

@@ -38,7 +38,7 @@ class TestSiteHttps(unittest.TestCase):
         is_redirect=result.is_redirect,
         is_permanent_redirect=result.is_permanent_redirect,
         status_code=result.status_code,
-        location=result.headers['Location']
+        location=result.headers.get('Location')
       ),
       dict(
         ok=True,
@@ -64,7 +64,7 @@ class TestSiteHttps(unittest.TestCase):
         is_redirect=result.is_redirect,
         is_permanent_redirect=result.is_permanent_redirect,
         status_code=result.status_code,
-        location=result.headers['Location']
+        location=result.headers.get('Location')
       ),
       dict(
         ok=True,