Only allow item selection if orgs are non-empty

The org count being empty means they did not successfully
load so don't allow further navigation in this case.

Author: kevinsawicki

app/src/main/java/com/github/mobile/ui/user/HomeActivity.java

@@ -216,7 +216,7 @@ public boolean onNavigationItemSelected(int itemPosition, long itemId) {
         if (homeAdapter.isOrgPosition(itemPosition)) {
             homeAdapter.setSelected(itemPosition);
             setOrg(orgs.get(itemPosition));
-        } else {
+        } else if (homeAdapter.getOrgCount() > 0) {
             switch (homeAdapter.getAction(itemPosition)) {
             case ACTION_GISTS:
                 startActivity(new Intent(this, GistsActivity.class));

app/src/main/java/com/github/mobile/ui/user/HomeDropdownListAdapter.java

@@ -83,7 +83,7 @@ public HomeDropdownListAdapter(final Context context,
      *
      * @return org count
      */
-    private int getOrgCount() {
+    public int getOrgCount() {
         return getCount() - NON_ORG_ITEMS;
     }