Removing redundant calls to GitHub.

The recurring usage of hub.getMyself() would eagerly
eat up the GitHub API allowance and artificially
produce lots of 502 errors.

Change-Id: I80fe09828eacd1fe98469ac76c58f1794cacba13

github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubLogin.java

diff --git a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubLogin.java b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubLogin.java
index b7f45ed..38a0eb6 100644
--- a/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubLogin.java
+++ b/github-oauth/src/main/java/com/googlesource/gerrit/plugins/github/oauth/GitHubLogin.java
@@ -73,7 +73,7 @@
 
   public boolean isLoggedIn(Set<Scope> scopes) {
     boolean loggedIn = scopesSet.equals(scopes) && token != null && hub != null;
-    if (loggedIn) {
+    if (loggedIn && myself == null) {
       try {
         myself = hub.getMyself();
       } catch (Throwable e) {