appveyor: PHP is downloaded using cURL

"03/mar/2018: We've upgraded the server bandwidth. This is however still not sufficient to handle all empty user agent connections. Please update the user agent in your scripts accordingly or contact us so we can discuss it."

Author: dg

appveyor.yml

@@ -14,8 +14,8 @@ install:
     # Install PHP
     - IF EXIST c:\php (SET PHP=0) ELSE (mkdir c:\php)
     - IF %PHP%==1 cd c:\php
-    - IF %PHP%==1 appveyor DownloadFile http://windows.php.net/downloads/releases/archives/php-7.1.0-Win32-VC14-x64.zip
-    - IF %PHP%==1 7z x php-7.1.0-Win32-VC14-x64.zip >nul
+    - IF %PHP%==1 curl https://windows.php.net/downloads/releases/archives/php-7.1.0-Win32-VC14-x64.zip --output php.zip
+    - IF %PHP%==1 7z x php.zip >nul
     - IF %PHP%==1 echo extension_dir=ext >> php.ini
     - IF %PHP%==1 echo extension=php_openssl.dll >> php.ini
     - IF %PHP%==1 del /Q *.zip