tls.Config: allow to configure ServerName

contrib/sample-cfg.yml

@@ -35,10 +35,11 @@ cookie:
     # gc-interval: 5m
     # sync:
     #   interval: 10s
-    #   base-url: http://localhost:1234
+    #   base-url: https://localhost:1234
     #   token: this-is-a-very-secret-token
     #   tls:
     #     insecure-skip-verify: true
+    #     server-name: login.example.com
     #     ca-certificates-data: |
     #       -----BEGIN CERTIFICATE-----
     #       ...

go.mod

@@ -34,7 +34,7 @@ require (
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/shurcooL/httpfs v0.0.0-20230704072500-f1e31cf0ba5c // indirect
 	github.com/shurcooL/vfsgen v0.0.0-20230704071429-0000e147ea92 // indirect
-	github.com/spreadspace/tlsconfig v0.0.0-20231119132223-bc653b6ec18f // indirect
+	github.com/spreadspace/tlsconfig v0.0.0-20231129213106-7ef966400fd3 // indirect
 	github.com/tg123/go-htpasswd v1.2.1 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/ugorji/go/codec v1.2.11 // indirect

go.sum

@@ -91,6 +91,8 @@ github.com/shurcooL/vfsgen v0.0.0-20230704071429-0000e147ea92 h1:OfRzdxCzDhp+rsK
 github.com/shurcooL/vfsgen v0.0.0-20230704071429-0000e147ea92/go.mod h1:7/OT02F6S6I7v6WXb+IjhMuZEYfH/RJ5RwEWnEo5BMg=
 github.com/spreadspace/tlsconfig v0.0.0-20231119132223-bc653b6ec18f h1:x7TdHxuYalzj2hjX1TIRNnqEaE3PeY/0DLiLcsHLlKA=
 github.com/spreadspace/tlsconfig v0.0.0-20231119132223-bc653b6ec18f/go.mod h1:taZ6lrQmZk4/XnC6stKWRIFSnj6SeBvtZ4nyAjN4nig=
+github.com/spreadspace/tlsconfig v0.0.0-20231129213106-7ef966400fd3 h1:LaFJ3pF+SsIeqoNpget+y/+PwtMPIhF3w/p993sLKvo=
+github.com/spreadspace/tlsconfig v0.0.0-20231129213106-7ef966400fd3/go.mod h1:taZ6lrQmZk4/XnC6stKWRIFSnj6SeBvtZ4nyAjN4nig=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=