Fix VLC builds

Based on the work in fdroidserver#224 (closed) and fdroidserver!204 (merged), this enables building VLC 2.0.6. fdroidserver!204 (merged) is already on the buildserver. This merge request should in theory work, but there might be some hiccups on the f-droid.org buildserver. In any case, I think its worth merging since its close, then we can fix things as they are reported from https://f-droid.org/wiki/page/org.videolan.vlc/lastbuild

@krt @est one question I have is: why not let the upstream ./compile.sh script handle downloading vlc.git and jpegsrc.v9a.tar.gz? This whole setup is complicated enough as it is. I think we should aim to keep this as close to upstream as possible to ensure that this keeps building.

More context here: https://code.videolan.org/videolan/vlc-android/issues/208