lib/pkgdb_conversion.c: remove metafile-sha256 obj if pkg contains no files.
lib/pkgdb_conversion.c: remove metafile-sha256 obj if pkg contains no files.

ebfe/xbps,ebfe/xbps,ebfe/xbps,datenwolf/xbps,stpx/xbps,stpx/xbps,datenwolf/xbps,stpx/xbps,datenwolf/xbps