regexp fix for python 3.7. Replace '[[]' with '\['
regexp fix for python 3.7. Replace '[[]' with '\['

  * python3.7.0 added FutureWarning for regexps that will conflict with a
    future upgrade to python regexp to support unicode nested sets.

    https://docs.python.org/3/whatsnew/3.7.html

Change-Id: I8d135d0dde463fb407ddfa1de3a76219b376680b
(cherry picked from commit 01333f95ea34eac82617b06695a7cfd0408e731d)

intelxed/xed,intelxed/xed,intelxed/xed,intelxed/xed