Silence Valid authors debug msg in presubmit

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 34ab6be252d759ddf49802430cd68afc69b0ecc0..17e309115b12ffa2cb32e45c72450f0ae58d06cf 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -774,9 +774,8 @@ def _CheckAuthorizedAuthor(input_api, output_api):
       input_api.re.match(r'[^#]+\s+\<(.+?)\>\s*$', line)
       for line in open(authors_path))
   valid_authors = [item.group(1).lower() for item in valid_authors if item]
-  if input_api.verbose:
-    print 'Valid authors are %s' % ', '.join(valid_authors)
   if not any(fnmatch.fnmatch(author.lower(), valid) for valid in valid_authors):
+    input_api.logging.info('Valid authors are %s', ', '.join(valid_authors))
     return [output_api.PresubmitPromptWarning(
         ('%s is not in AUTHORS file. If you are a new contributor, please visit'
         '\n'