import is duplicated in certain situation

[youxkei]

Version: v1.1.0
The reproduction code: https://github.com/youxkei/goimportz-bug/tree/f2953b59fedf2fe37b3965d2007ea078765d9c25

$ cat a.go
package main

import (
	"example.com/hoge-a"
	"example.com/hoge-b"
)

func f()  {
	hogea.F()
}

$ go run github.com/zchee/goimportz/cmd/goimportz a.go
package main

import (
	"example.com/hoge-a"
	hogea "example.com/hoge-a"
)

func f() {
	hogea.F()
}

In the above situation, gimportz somehow outputs source code in which "hoge-a" package is imported twice.