protobuf in dldt-ie.m4

[xwu2git]

(1) The code is not from a released tag.
(2) The installation is not to /usr/local/lib.

[xwu2git]

Also, protobuf seems to be installed multiple times in dldt-ie.m4.
Once explicitly, the other time part of pip install requirements.

[xwu2git]

There is another one in opencv.m4.

[dpatel257]

There is another one in opencv.m4.

@xwu2git Couldn't find the one in opencv.m4. Is this comment still relevant?

[jhou5]

#442