[Buildroot] Patch for opencv3: python module was built for the host instead of target.

[Peter Korsgaard]

>>>>> "Shyrokov," == Shyrokov, Sasha <Sasha-Shyrokov at idexx.com> writes:

 > From 9b211fb5ec49879d10d32d22ed3608ffca944e2d Mon Sep 17 00:00:00 2001
 > From: Sasha Shyrokov <alexander-shyrokov at idexx.com>
 > Date: Tue, 6 Mar 2018 10:58:10 -0500
 > Subject: [PATCH 1/1] opencv3: python module was built for the host instead of target.

 > distutils environment variables must be set.
 > OPENCV3_CONF_ENV = $(PKG_PYTHON_DISTUTILS_ENV) All credit goes to Arnout:
 > https://stackoverflow.com/questions/49059035/buildroot-opencv3-python-package-builds-for-the-wrong-target

 > Signed-off-by: Sasha Shyrokov <alexander-shyrokov at idexx.com>

Committed to 2018.02.x, thanks.

-- 
Bye, Peter Korsgaard