Toml cannot be used map

[xweis]

#config.toml 
title       = "blabla"
[servers]
    [servers.a]
    ip      = "1.1.1.1"
    dc      = "abc"
    [servers.b]
    ip      = "2.2.2.2"
    dc      = "cba"


#main.go
type (
	WebSiteConfig struct {
		Title string
		Servers map[string]Server
	}
)

type Server struct {
		IP string
		DC string
}

func Load() *WebSiteConfig {
	config := new(WebSiteConfig)
	multiconfig.NewWithPath(LogPath). MustLoad(config)

	return config
}


#error 
panic: not struct

goroutine 1 [running]:
github.com/fatih/structs.strctVal(0xc0001c4500, 0xc0001b88f8, 0x16, 0xc0001c4500, 0xc0001b88f8)
        /Users/Xwei/go/src/github.com/fatih/structs/structs.go:437 +0x12f
github.com/fatih/structs.(*Field).FieldOk(0xc0002122d0, 0xc0002143c2, 0x1, 0xc0001ddc80, 0xc0001caa10)
        /Users/Xwei/go/src/github.com/fatih/structs/field.go:129 +0x98
github.com/fatih/structs.(*Field).Field(0xc0002122d0, 0xc0002143c2, 0x1, 0x157ad93)
        /Users/Xwei/go/src/github.com/fatih/structs/field.go:109 +0x3f
github.com/koding/multiconfig.(*EnvironmentLoader).processField(0xc0001c02a0, 0x1596ef3, 0xd, 0xc0002122d0, 0x157ad93, 0x7, 0x15fa320, 0xc0001b93b0, 0x0, 0x0)
        /Users/Xwei/go/src/github.com/koding/multiconfig/env.go:61 +0x164
github.com/koding/multiconfig.(*EnvironmentLoader).Load(0xc0001c02a0, 0x15c80e0, 0xc0001b88d0, 0x0, 0x0)

[AlanW0ng]

#config.toml 
title       = "blabla"
[servers]
    [servers.a]
    ip      = "1.1.1.1"
    dc      = "abc"
    [servers.b]
    ip      = "2.2.2.2"
    dc      = "cba"


#main.go
type (
	WebSiteConfig struct {
		Title string
		Servers map[string]Server
	}
)

type Server struct {
		IP string
		DC string
}

func Load() *WebSiteConfig {
	config := new(WebSiteConfig)
	multiconfig.NewWithPath(LogPath). MustLoad(config)

	return config
}


#error 
panic: not struct

goroutine 1 [running]:
github.com/fatih/structs.strctVal(0xc0001c4500, 0xc0001b88f8, 0x16, 0xc0001c4500, 0xc0001b88f8)
        /Users/Xwei/go/src/github.com/fatih/structs/structs.go:437 +0x12f
github.com/fatih/structs.(*Field).FieldOk(0xc0002122d0, 0xc0002143c2, 0x1, 0xc0001ddc80, 0xc0001caa10)
        /Users/Xwei/go/src/github.com/fatih/structs/field.go:129 +0x98
github.com/fatih/structs.(*Field).Field(0xc0002122d0, 0xc0002143c2, 0x1, 0x157ad93)
        /Users/Xwei/go/src/github.com/fatih/structs/field.go:109 +0x3f
github.com/koding/multiconfig.(*EnvironmentLoader).processField(0xc0001c02a0, 0x1596ef3, 0xd, 0xc0002122d0, 0x157ad93, 0x7, 0x15fa320, 0xc0001b93b0, 0x0, 0x0)
        /Users/Xwei/go/src/github.com/koding/multiconfig/env.go:61 +0x164
github.com/koding/multiconfig.(*EnvironmentLoader).Load(0xc0001c02a0, 0x15c80e0, 0xc0001b88d0, 0x0, 0x0)

+1, TOML map lead to "panic struct" error