Fix web project build with dotnet build command

[kirill-d-lappo]

Web project can't be built with dotnet build command, which doesn't allow to use dotnet ef commands when migrating database

PackageTargetFallback - dotnet build returns

C:\workspace\github.com\kira-lappo\AlpineSkiHouse\src\AlpineSkiHouse.Web\AlpineSkiHouse.Web.csproj : error NU1003: PackageTargetFallback and AssetTargetFallback cannot be used together. Remove PackageTargetFallback(deprecated) references from the project environment.

Solution - remove PackageTargetFallback from namespace AlpineSkiHouse.Web.csproj