tools/gnulib: use exact directory copy for install

tools/gnulib: use exact directory copy for install

The python implementation of gnulib-tool
uses a hidden file as the independent main function.

A copy with glob ('*') does not include hidden files
at the top level directory, so use whole directory copy
instead and remove the patch for a non-hidden python file.

Ensure the directory does not already exist
by attempting uninstall first to remove it
and by not using "install" to create a directory.

Rename the clean target to uninstall, as it handles
the staging directory and not the build directory.

Removed:
 - 021-python-main.patch

Signed-off-by: Michael Pratt <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/16522
Signed-off-by: Robert Marko <[email protected]>