Fixed user check in cron environment

tester.py

@@ -107,7 +107,7 @@ class Tester:
                     log("USAGE: " + self.USAGE)
                     sys.exit(1)
             else:
-                log("Optional target user : %s" % arg)
+                log("Optional target user: %s" % arg)
                 if not os.path.isdir(os.path.join("/home", arg)):
                     log("Mediaserver user %s does not exist" % arg)
                     sys.exit(1)
@@ -123,7 +123,7 @@ class Tester:
             sys.path.append(root_dir)
         # Check that this script is run by root
         debug = "-d" in args
-        if os.environ.get("USER") != "root" and not debug:
+        if os.getuid() != 0 and not debug:
             log("This script should be run as root user.")
             sys.exit(1)
         # Update envsetup files