Drop unnecessary nonce parameters

#132
refactored the test so that nonce is automatically generated.

Author: stanhu

test/lib/omniauth/strategies/openid_connect_test.rb

@@ -280,7 +280,6 @@ def test_callback_phase_with_discovery # rubocop:disable Metrics/AbcSize
 
       def test_callback_phase_with_no_state_without_state_verification # rubocop:disable Metrics/AbcSize
         code = SecureRandom.hex(16)
-        nonce = SecureRandom.hex(16)
 
         strategy.options.require_state = false
 
@@ -325,7 +324,6 @@ def test_callback_phase_with_no_state_without_state_verification # rubocop:disab
       def test_callback_phase_with_invalid_state_without_state_verification
         code = SecureRandom.hex(16)
         state = SecureRandom.hex(16)
-        nonce = SecureRandom.hex(16)
 
         strategy.options.require_state = false