libopenshot: fix python3 detection

srcpkgs/libopenshot/template

@@ -1,12 +1,12 @@
 # Template file for 'libopenshot'
 pkgname=libopenshot
 version=0.2.3
-revision=2
+revision=3
 archs="i686 x86_64 ppc64le"
 build_style=cmake
 pycompile_module="openshot.py"
 configure_args="-DENABLE_RUBY=OFF -DUSE_SYSTEM_JSONCPP=ON" # Builds fail with Ruby-2.4.1
-hostmakedepends="swig doxygen ruby python3"
+hostmakedepends="swig doxygen ruby python3 pkg-config"
 makedepends="python3-devel ffmpeg-devel libmagick-devel qt5-devel libgomp-devel
  libopenshot-audio-devel qt5-multimedia-devel unittest-cpp zeromq-devel cppzmq
  jsoncpp-devel"
@@ -19,6 +19,11 @@ distfiles="https://github.com/OpenShot/libopenshot/archive/v${version}.tar.gz"
 checksum=8536b0a790b0d98ed4c3b10e11d1b34ae68ccbc710887e3703a5143d95598746
 patch_args="-Np1"
 
+pre_configure() {
+  # vendored python cmake module does not find python 3.8
+  rm cmake/Modules/FindPythonLibs.cmake
+}
+
 libopenshot-devel_package() {
 	short_desc+=" - development files"
 	pkg_install() {