Don't require SIGNTOOL_PARAMS to contain the 'sign' command

scripts/build-arch.bat

@@ -27,7 +27,7 @@ if /I "%BUILD_CONFIG%"=="debug" (
             )
 
             if not defined SIGNTOOL_PARAMS (
-                echo "A signtool parameter string must be specified in SIGNTOOL_PARAMS for signed release builds"
+                echo A signtool parameter string must be specified in SIGNTOOL_PARAMS for signed release builds
                 exit /b 1
             )
 
@@ -280,7 +280,7 @@ if "%SIGN%"=="1" (
     for /r "%DEPLOY_FOLDER%" %%f in (*.dll *.exe) do (
         set FILES_TO_SIGN=!FILES_TO_SIGN! %%f
     )
-    signtool %SIGNTOOL_PARAMS% !FILES_TO_SIGN!
+    signtool sign %SIGNTOOL_PARAMS% !FILES_TO_SIGN!
     if !ERRORLEVEL! NEQ 0 goto Error
 )