package/zxing-cpp: replace ZXING_CPP_MAKE_OPTS workaround

Bumping to version e0e40dd in commit
ad9c5bbf included the following upstream
commit:
https://github.com/glassechidna/zxing-cpp/commit/4e2b4fe1668c60d73e7649b0d3d5888912878392



This commit contains CMake improvements and especially a new
BUILD_TESTING option that disable the testrunner compile, use this
instead of the ZXING_CPP_MAKE_OPTS workaround.

Reviewed-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>