supress debug message if not run in a terminal

Signed-off-by: Mattia Rizzolo <mapreri@ubuntu.com>

cron.sh

@@ -12,7 +12,10 @@ fi
 
 run_script() (
     if [[ ! -x "${script}" ]]; then
-        echo "$(basename "$script"): not executable, skipping"
+        # suppress message if not running in a terminal
+        if [[ -t 1 ]]; then
+            echo "$(basename "$script"): not executable, skipping"
+        fi
         return
     fi
     # Create a temporary build directory