update download url for Shell.efi

Signed-off-by: Christian Hesse <mail@eworm.de>

configs/releng/build.sh

@@ -168,7 +168,7 @@ make_efi() {
         ${script_path}/efiboot/loader/entries/archiso-x86_64-usb.conf > ${work_dir}/iso/loader/entries/archiso-x86_64.conf
 
     # EFI Shell 2.0 for UEFI 2.3+
-    curl -o ${work_dir}/iso/EFI/shellx64_v2.efi https://raw.githubusercontent.com/tianocore/edk2/master/ShellBinPkg/UefiShell/X64/Shell.efi
+    curl -o ${work_dir}/iso/EFI/shellx64_v2.efi https://raw.githubusercontent.com/tianocore/edk2/UDK2018/ShellBinPkg/UefiShell/X64/Shell.efi
     # EFI Shell 1.0 for non UEFI 2.3+
     curl -o ${work_dir}/iso/EFI/shellx64_v1.efi https://raw.githubusercontent.com/tianocore/edk2/UDK2018/EdkShellBinPkg/FullShell/X64/Shell_Full.efi
 }