Merge pull request #1936 from jan-cerny/pkgconfig

Fix OS X build

Author: ggbecker

.github/workflows/build.yml

@@ -93,6 +93,7 @@ jobs:
         brew update
         brew install doxygen
         brew install opendbx
+        brew install pkg-config
         brew install popt
         brew install swig
         brew install libxmlsec1