bump up rootlesskit to v0.4.1

Now the child process is killed when the parent dies (rootless-containers/rootlesskit#66)

https://github.com/rootless-containers/rootlesskit/compare/e92d5e7...27a0c7a

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

hack/dockerfile/install/rootlesskit.installer

@@ -1,7 +1,7 @@
 #!/bin/sh
 
-# v0.4.0
-ROOTLESSKIT_COMMIT=e92d5e772ee7e103aecf380c5874a40c52876ff0
+# v0.4.1
+ROOTLESSKIT_COMMIT=27a0c7a2483732b33d4192c1d178c83c6b9e202d
 
 install_rootlesskit() {
 	case "$1" in