Postpone keys setup until after PUSH_REPLY

And rename to setupEncryption() for ambiguity with SessionKey.

TunnelKit/Sources/Core/SessionProxy.swift

@@ -848,8 +848,6 @@ public class SessionProxy {
                 return
             }
             
-            setupKeys()
-
             negotiationKey.controlState = .preIfConfig
             nextPushRequestDate = Date().addingTimeInterval(negotiationKey.softReset ? CoreConfiguration.softResetDelay : CoreConfiguration.retransmissionLimit)
             pushRequest()
@@ -891,6 +889,8 @@ public class SessionProxy {
             return
         }
         
+        setupEncryption()
+        
         authenticator = nil
         negotiationKey.startHandlingPackets(
             withPeerId: peerId,
@@ -1007,7 +1007,7 @@ public class SessionProxy {
     }
     
     // Ruby: setup_keys
-    private func setupKeys() {
+    private func setupEncryption() {
         guard let auth = authenticator else {
             fatalError("Setting up keys without having authenticated")
         }