[ASPNETCORE] bad character in generated file

[Bobdugrand8]

Description
When using the generator for ASPNETCORE, it add a bad character that blocks the project to open.

Swagger-codegen version
3.0.51 on https://editor.swagger.io/

Swagger declaration file content or url
The default PETStore is also bugged

Command line used for generation
Steps to reproduce
Generate the aspnetcore server.
Try to open the project in visual studio (or rider)
The project fail to open.

Related issues/PRs
Suggest a fix/enhancement
The error is in IO.swagger.csproj:

[HugoMario]

fixed by #1233