build: More meson version fixes
The "install arg in configure_file" from 0.50.0 was still being used in other places. Make sure to remove its use completely to support meson 0.49.0 as required in the top-level meson.build.
WARNING: Project specifies a minimum meson_version '>= 0.49.0' but uses features which were added in newer versions:
* 0.50.0: {'install arg in configure_file'}
Follow-up on b6c23eb2