title: Error: connect ECONNREFUSED 127.0.0.1:8100
body: <p>Could you help with this problem.
  Appium 1.7.1
  Xcode- 9.0
  MacOS Siera 10.13</p>
  
  <p>Capabilities:
  {
    "platformName": "iOS",
    "platformVersion": "11.0",
    "deviceName": "iPhone 6",
    "app": "/Users/akoval/Downloads/BusyBox.app"
  }</p>
  
  <p>An unknown server-side error occurred while processing the command. Original error: Unable to start WebDriverAgent session because of xcodebuild failure: An unknown server-side error occurred while processing the command. Original error: Could not proxy command to remote server. Original error: Error: connect ECONNREFUSED 127.0.0.1:8100</p>