API 2: compact mode

In 15.2.2 the compact mode in API 2 was introduced on the director side
and as the webui makes use of this mode the minimum requirement is
a working director equal or greater than 15.2.2, otherwise webui won't
connect to the director.

vendor/Bareos/library/Bareos/BSock/BareosBSock.php

@@ -852,7 +852,7 @@ public function send_command($cmd, $api=0, $jobid=null)
                $debug = self::receive_message();
                if(!preg_match('/result/', $debug)) {
                   throw new \Exception("Error: API 2 not available on director.
-                  Please upgrade to version 15.2.1 or greater and/or compile with jansson support.");
+                  Please upgrade to version 15.2.2 or greater and/or compile with jansson support.");
                }
             }
             catch(\Exception $e) {