tools/: use safe yaml loading

YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as
the default Loader is unsafe. Please read https://msg.pyyaml.org/load for
full details.

tools/make-summary-translatable.py

@@ -11,7 +11,7 @@ os.chdir(os.path.dirname(__file__) + '/../')
 for f in glob.glob('metadata/*.yml'):
     with open(f) as fp:
         raw = fp.read()
-        data = yaml.load(raw)
+        data = yaml.safe_load(raw)
     archive_policy = data.get('ArchivePolicy')
     if (
         'Disabled' not in data

tools/rewrite-git-redirects.py

@@ -21,7 +21,7 @@ else:
 pattern = re.compile(r'Repo: .*')
 for f in files:
     with open(f) as fp:
-        data = yaml.load(fp)
+        data = yaml.safe_load(fp)
     repo_url = None
     if 'Repo' in data:
         repo_url = data['Repo'].strip().rstrip('/')