PR revision: retrieve timeserver key metadata correctly

The mechanism for retrieving metadata from the TAP4-conforming
multi-repository-updater is the Updater.get_metadata() call.

Note that until the test metadata includes timeserver keys,
the tests will still fail.

Signed-off-by: Sebastien Awwad <sebastien.awwad@gmail.com>

Author: awwad

uptane/clients/primary.py

@@ -358,8 +358,8 @@ def refresh_toplevel_metadata_from_repositories(self):
 
 
     # Make note of the currently-trusted Timeserver key.
-    current_trusted_timeserver_key = \
-          self.updater.metadata['current']['root']['roles']['timeserver']
+    current_trusted_timeserver_key = self.updater.get_metadata(
+        self.director_repo_name, 'current')['root']['roles']['timeserver']
 
     try:
       self.updater.refresh()
@@ -379,8 +379,8 @@ def refresh_toplevel_metadata_from_repositories(self):
         self.updater.refresh()
 
     else:
-      new_trusted_timeserver_key = \
-          self.updater.metadata['current']['root']['roles']['timeserver']
+      new_trusted_timeserver_key = self.updater.get_metadata(
+        self.director_repo_name, 'current')['root']['roles']['timeserver']
 
       if current_trusted_timeserver_key != new_trusted_timeserver_key:
         self.reset_clock()