feat: docker download dir move to /app/Download (#398)

pkg/base/info.go

@@ -2,6 +2,7 @@ package base
 
 // Version is the build version, set at build time, using `go build -ldflags "-X github.com/GopeedLab/gopeed/pkg/base.Version=1.0.0"`.
 var Version string
+var InDocker bool
 
 func init() {
 	if Version == "" {