Use the later (v4.3.0) NuGet

bootstrapper.ps1

@@ -91,7 +91,7 @@ $ADDINS_DIR = Join-Path $TOOLS_DIR "addins"
 $MODULES_DIR = Join-Path $TOOLS_DIR "modules"
 $NUGET_EXE = Join-Path $TOOLS_DIR "nuget.exe"
 $CAKE_EXE = Join-Path $TOOLS_DIR "Cake/Cake.exe"
-$NUGET_URL = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
+$NUGET_URL = "https://dist.nuget.org/win-x86-commandline/v4.3.0/nuget.exe"
 $PACKAGES_CONFIG = Join-Path $TOOLS_DIR "packages.config"
 $PACKAGES_CONFIG_MD5 = Join-Path $TOOLS_DIR "packages.config.md5sum"
 $ADDINS_PACKAGES_CONFIG = Join-Path $ADDINS_DIR "packages.config"

bootstrapper.sh

@@ -74,7 +74,7 @@ fi
 # Download NuGet if it does not exist.
 if [ ! -f "$NUGET_EXE" ]; then
     echo "Downloading NuGet..."
-    curl -Lsfo "$NUGET_EXE" https://dist.nuget.org/win-x86-commandline/latest/nuget.exe
+    curl -Lsfo "$NUGET_EXE" https://dist.nuget.org/win-x86-commandline/v4.3.0/nuget.exe
     if [ $? -ne 0 ]; then
         echo "An error occured while downloading nuget.exe."
         exit 1