config-tools: remove unused package and add nosec to subprocess

The subprocess module is needed for calling package from python script.
Add #nosec for subprocess module importing.

Tracked-On: #6342
Signed-off-by: Yang,Yu-chu <yu-chu.yang@intel.com>

misc/config_tools/library/common.py

@@ -7,7 +7,7 @@ import os
 import sys
 import getopt
 import shutil
-import subprocess
+import subprocess # nosec
 import xml.etree.ElementTree as ET
 import re
 import lxml