Some small issues with the translation of the import control

## Describe the bug
Some typos and a non-translatable error message.

## To Reproduce
File: importcsv.ascx.resx
Key: Error.Text
Value: An error occurred during the export
Value should be "An error occurred during the import"

File: importcsv.ascx.cs
Line: 129
"Please specify the file to import" should be localizable.
