SetColStyle not honoring given style

Created by: SteveTalt

Description SetColStyle seems to be corrupting spreadsheets. It doesn't seem to matter what data is in the column or which column or sheet you use.

I created this simple code to re-produce it:

package main

import (
	"github.com/excelize"
)

// define globals

var xlfile = "testlocal.xlsx"
var xlsheetname = "test"

// main
func main() {
	var (
		file *excelize.File
		err  error
	)
	// open the file
	file, err = excelize.OpenFile(xlfile)
	errorhandler(err)

	err = file.SetColStyle(xlsheetname, "C", 7)
	errorhandler(err)
	file.Save()

}

func errorhandler(e error) {
	if e != nil {
		panic(e)
	}
}

Steps to reproduce the issue:

1. Create a spreadsheet named localtest.xlsx and a sheet named test
2. run this test code against it
3. open the spreadsheet and see it needs repair

Describe the results you received: Repair Log: `

Repair Result to testlocal5.xml

Errors were detected in file '/Users/stalt/Documents/go/src/setcoltest/testlocal.xlsx'

Repaired Records: Column information from /xl/worksheets/sheet1.xml part

`

Describe the results you expected: I expect the column to be formated with

Output of go version:

$ go version
go version go1.10 darwin/amd64

Excelize version or commit ID:

commit id: 448f552

Environment details (OS, Microsoft Excel™ version, physical, etc.): macOS Mojave 10.14.5 Excel for Mac 16.27 (19071500)