[config]: fix the runtime error of the 'show line' command (sonic-net#595) (sonic-net#596)

Signed-off-by: wangshengjun <wangshengjun@asterfusion.com>

Author: wangshengjun

consutil/__init__.py

@@ -11,7 +11,9 @@
     import pexpect
     import re
     import subprocess
+    import sys
     from tabulate import tabulate
+    from lib import *
 except ImportError as e:
     raise ImportError("%s - required module not found" % str(e))