conscrypt: change test of SSL_set_cipher_lists

NativeCrypto.SSL_set_cipher_lists can accept the empty list as
per c/154191

Bug: 21816861

(cherry picked from commit c0010ca585f9cdc1f09846e2d75a0a8f82420476)

Change-Id: I6cf7563417d8b6fb9edbeade0947726275a76c18
1 file changed