Update custom encoding section of Readme.md (#2035)
Update custom encoding section of Readme.md (#2035)

urlRequest property of URLRequestConvertible is optional, so you have to unwrap it or make non-optional.
easyui/Alamofire,Lomotif/Alamofire,richardPFisk/Alamofire,iosheadhunter/Alamofire,Alamofire/Alamofire,yimajo/Alamofire,yimajo/Alamofire,Alamofire/Alamofire,antigp/Alamofire,antigp/Alamofire,Lomotif/Alamofire,iosheadhunter/Alamofire,richardPFisk/Alamofire,easyui/Alamofire,jschmid/Alamofire,jschmid/Alamofire