[test] skip the ec integration test on 1.8.7 due loading 1.9 syntax code

Author: kares

src/test/ruby/ec/test_ec.rb

@@ -100,7 +100,7 @@ def test_encrypt_integration # inspired by WebPush
       :auth => Base64.urlsafe_decode64(auth))
 
     assert_equal "Hello World", decrypted_data
-  end
+  end if RUBY_VERSION > '1.9'
 
   def generate_ecdh_key(group = 'prime256v1')
     curve = OpenSSL::PKey::EC.new(group)