Fixed incorrect test case of test_server_metadata.py

Fixed incorrect test case about following points.
 * delete 2 test case because same test will be done
   in other part of same class.
 * fixed parameter according to test purpose.
 * fixed expected exception code.

Change-Id: I3116e9b4e22a86c583a531c8b8e46069f876296e
Merge "Fixed incorrect test case of test_server_metadata.py"