Update appveyor.yml

Author: SimonCropp

src/appveyor.yml

@@ -10,11 +10,11 @@ build_script:
 - ipconfig /flushdns
 - pwsh: |
     if ($isWindows) {
-      Invoke-WebRequest "https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.ps1" -OutFile "./dotnet-install.ps1" -TimeoutSec 120
+      Invoke-WebRequest "https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.ps1" -OutFile "./dotnet-install.ps1"
       ./dotnet-install.ps1 -JSonFile src/global.json -Architecture x64 -InstallDir 'C:\Program Files\dotnet'
     }
     else {
-      Invoke-WebRequest "https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.sh" -OutFile "./dotnet-install.sh" -TimeoutSec 120
+      Invoke-WebRequest "https://dotnet.microsoft.com/download/dotnet/scripts/v1/dotnet-install.sh" -OutFile "./dotnet-install.sh"
       sudo chmod u+x dotnet-install.sh
       if ($isMacOS) {
         sudo ./dotnet-install.sh --jsonfile src/global.json --architecture x64 --install-dir '/usr/local/share/dotnet'