RemoveRow with merged cells will cause the next row which originally does not contain merged cells to have merged cells

[tianhai82]

I have a spreadsheet with merged cells on row 1 (F1:H1).
After I call file.RemoveRow("Sheet1",1), the new row 1 which originally does not contain any merged cells will have F1:H1 merged.
test.xlsx

	file, err := excelize.OpenFile("test.xlsx")
	file.RemoveRow("Sheet1", 1)
	file.SaveAs("out.xlsx")

Output of go version:
go version go1.12.1 windows/amd64

Excelize version or commit ID:
2.0

Environment details (OS, Microsoft Excel™ version, physical, etc.):
Windows 10, Excel 2016

[xuri]

HI @tianhai82, thanks for your issue. I have fixed it. Please try to upgrade the library with the master branch code.