[Issue #1818] Added macOS disclaimer to download request example in README.
[Issue #1818] Added macOS disclaimer to download request example in README.

iosheadhunter/Alamofire,Alamofire/Alamofire,easyui/Alamofire,Farteen/Alamofire,richardPFisk/Alamofire,easyui/Alamofire,Lomotif/Alamofire,richardPFisk/Alamofire,iosheadhunter/Alamofire,Noobish1/Alamofire,antigp/Alamofire,yimajo/Alamofire,yimajo/Alamofire,Farteen/Alamofire,Lomotif/Alamofire,Noobish1/Alamofire,antigp/Alamofire,jschmid/Alamofire,Alamofire/Alamofire,jschmid/Alamofire