Remove unused libraries from nsjail.py

Change-Id: Id4d9cc92853ff27ebea90b886982855e4b6ba8b2
diff --git a/build/sandbox/nsjail.py b/build/sandbox/nsjail.py
index 80a4f90..4bbc410 100644
--- a/build/sandbox/nsjail.py
+++ b/build/sandbox/nsjail.py
@@ -26,8 +26,6 @@
 import re
 import subprocess
 from .overlay import BindOverlay
-import tempfile
-import glob
 
 _DEFAULT_META_ANDROID_DIR = 'LINUX/android'
 _DEFAULT_COMMAND = '/bin/bash'