docs(vapi): fix incorrect call control URL

docs(vapi): fix incorrect call control URL

The docs currently reference:
https://aws-us-west-2-production1-phone-call-websocket.vapi.ai

Updated to the correct endpoint:
https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai

Author: Imemario77

fern/calls/call-features.mdx

@@ -51,7 +51,7 @@ curl 'https://api.vapi.ai/call'
   "phoneCallTransport": "pstn",
   "monitor": {
     "listenUrl": "wss://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/transport",
-    "controlUrl": "<https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control>"
+    "controlUrl": "<https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control>"
   }
 }
 
@@ -65,7 +65,7 @@ Once you have the `controlUrl`, you can use various control features during a li
 Makes the assistant say a specific message during the call.
 
 ```bash
-curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
+curl -X POST 'https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
 -H 'content-type: application/json' 
 --data-raw '{
   "type": "say",
@@ -78,7 +78,7 @@ curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/742
 Adds a message to the conversation history and optionally triggers a response.
 
 ```bash
-curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
+curl -X POST 'https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
 -H 'content-type: application/json' 
 --data-raw '{
   "type": "add-message",
@@ -94,7 +94,7 @@ curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/742
 Control the assistant's behavior during the call.
 
 ```bash
-curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
+curl -X POST 'https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
 -H 'content-type: application/json' 
 --data-raw '{
   "type": "control",
@@ -106,7 +106,7 @@ curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/742
 Programmatically end the ongoing call.
 
 ```bash
-curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
+curl -X POST 'https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
 -H 'content-type: application/json' 
 --data-raw '{
   "type": "end-call"
@@ -117,7 +117,7 @@ curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/742
 Transfer the call to a different destination.
 
 ```bash
-curl -X POST 'https://aws-us-west-2-production1-phone-call-websocket.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
+curl -X POST 'https://phone-call-websocket.aws-us-west-2-backend-production2.vapi.ai/7420f27a-30fd-4f49-a995-5549ae7cc00d/control' 
 -H 'content-type: application/json' 
 --data-raw '{
   "type": "transfer",