build: adapt Arch Linux packaging

src/qEmbyCore/CMakeLists.txt

@@ -23,6 +23,10 @@ target_link_libraries(qEmbyCore PUBLIC Qt${QT_VERSION_MAJOR}::Gui
 
 target_compile_definitions(qEmbyCore PRIVATE QEMBYCORE_LIBRARY)
 
+if(COMMAND qemby_apply_build_options)
+    qemby_apply_build_options(qEmbyCore)
+endif()
+
 include(GNUInstallDirs)
 
 set(_qemby_core_library_install_dir "${CMAKE_INSTALL_LIBDIR}")