v0.4.1

Improvement based on golangci-lint

1583d0b222e1987cb6321b094655c6812596676df462d5090f51cb933da6cb85  ./better-dns-darwin-amd64
20816c417c68d83704e6c9744c8508736a040d5cbf5bb02de8a3b16bf8d4b04b  ./better-dns-linux-386
4ca1e90df1fe3366f813d371686c6c85f39966bd63fd3f5dc7eda81858c1aa90  ./better-dns-linux-amd64
c8e32ec43b0174d7e03ea1ac24717a1d471911c73a4a8c0a5cc5aaf1e0acaed1  ./better-dns-linux-arm
081825bbb01b6ece9845fbca989e96a1dbcd6887d09ac4d75ce1d62434e1f707  ./better-dns-linux-arm64
532cc1eccb99240afd60f61e582f0d907d2990eec73e8ed496f172e08cb35bdd  ./better-dns-windows-386.exe
1196ac89d2681c7f5198a05b06e455aa58fffc6cd6ea00b3c5c83bd37ba1b614  ./better-dns-windows-amd64.exe