Avoid wrnings in case we can't get the active branches for some reason

Author: rlerdorf

include/branches.inc

@@ -139,7 +139,9 @@ function get_active_branches($include_recent_eols = true) {
 				}
 			}
 		}
-		ksort($branches[$major]);
+		if (!empty($branches[$major])) {
+			ksort($branches[$major]);
+		}
 	}
 
 	ksort($branches);

index.php

@@ -98,7 +98,7 @@
 
 $intro .= "<ul>\n";
 foreach (get_active_branches() as $major => $releases) {
-    foreach ($releases as $release) {
+    foreach ((array)$releases as $release) {
         $version = $release['version'];
         list($major, $minor, $_) = explode('.', $version);
         $intro .= "