psr4ns(): fixed merging arrays of paths
psr4ns(): fixed merging arrays of paths

Both values (array)$list[$namespace] and (array) $paths
are numeric arrays
so result of "+" operation on them was not what we want.

przepompownia/phpcd.vim,lvht/phpcd.vim,przepompownia/phpcd.vim,lvht/phpcd.vim,lvht/phpcd.vim,przepompownia/phpcd.vim