Make unprivileged run less noisy (#217)

This makes the permission denied messages from mount and unshare more
visible.

Signed-off-by: Evangelos Lamprou <vagos@lamprou.xyz>

Author: vagos

try

@@ -325,7 +325,7 @@ EOF
         pure_mountpoint=${mountpoint##*:}
         if [  -L "$pure_mountpoint" ]
         then
-            rm "${SANDBOX_DIR}/temproot/${mountpoint}"
+            rm "${SANDBOX_DIR}/temproot/${mountpoint}" 2>"$try_mount_log"
         fi
     done <"$DIRS_AND_MOUNTS"