tools/msvc: radadd wrongly-deleted echo line

tools/msvc/starpu_clean.bat

@@ -1,3 +1,5 @@
+@ECHO OFF
+
 REM StarPU --- Runtime system for heterogeneous multicore architectures.
 REM
 REM Copyright (C) 2013-2015,2017                           CNRS

tools/msvc/starpu_exec.bat

@@ -1,3 +1,5 @@
+@ECHO OFF
+
 REM StarPU --- Runtime system for heterogeneous multicore architectures.
 REM
 REM Copyright (C) 2013-2015,2017                           CNRS

tools/msvc/starpu_open.bat

@@ -1,3 +1,5 @@
+@ECHO OFF
+
 REM StarPU --- Runtime system for heterogeneous multicore architectures.
 REM
 REM Copyright (C) 2013-2015,2017                           CNRS

tools/msvc/starpu_var.bat.in

@@ -1,3 +1,5 @@
+@ECHO OFF
+
 REM StarPU --- Runtime system for heterogeneous multicore architectures.
 REM
 REM Copyright (C) 2013-2017                                CNRS