Downgrading to INFO the GitHub Team access denials

When requesting to GitHub the list of Teams that a user belongs to
it is quite common to receive a permission denied error.
This is not a warning but just a normal situation when the user
do not allow to access his private information, which is a legal
scenario.

Change-Id: Icde491f2cd395419b42769aa15eb039f988fd50e
diff --git a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/group/GitHubGroupsCache.java b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/group/GitHubGroupsCache.java
index f895500..bf94d1c 100644
--- a/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/group/GitHubGroupsCache.java
+++ b/github-plugin/src/main/java/com/googlesource/gerrit/plugins/github/group/GitHubGroupsCache.java
@@ -77,7 +77,7 @@
       try {
         loadOrganisationsAndTeams(username, orgsTeams, ghLogin);
       } catch (FileNotFoundException teamsNotFound) {
-        log.warn(
+        log.info(
             "Cannot access teams for user '{}': falling back to list of public organisations",
             username);
         loadOrganisations(username, orgsTeams, ghLogin);