[iOS] Changed ptr to const ref for RTCConfiguration initialization

BUG=webrtc:7431

Review-Url: https://codereview.webrtc.org/2794193002
Cr-Commit-Position: refs/heads/master@{#17533}
diff --git a/webrtc/sdk/objc/Framework/UnitTests/RTCConfigurationTest.mm b/webrtc/sdk/objc/Framework/UnitTests/RTCConfigurationTest.mm
index fee2a49..cc6c493 100644
--- a/webrtc/sdk/objc/Framework/UnitTests/RTCConfigurationTest.mm
+++ b/webrtc/sdk/objc/Framework/UnitTests/RTCConfigurationTest.mm
@@ -99,7 +99,8 @@
 
   webrtc::PeerConnectionInterface::RTCConfiguration *nativeConfig =
       [config createNativeConfiguration];
-  RTCConfiguration *newConfig = [[RTCConfiguration alloc] initWithNativeConfiguration:nativeConfig];
+  RTCConfiguration *newConfig = [[RTCConfiguration alloc]
+      initWithNativeConfiguration:*nativeConfig];
   EXPECT_EQ([config.iceServers count], newConfig.iceServers.count);
   RTCIceServer *newServer = newConfig.iceServers[0];
   RTCIceServer *origServer = config.iceServers[0];