[http-server-csharp] extra blank lines are generated in the result

[ArcturusZhang]

For instance in this generated code:

    [ApiController]
    public abstract partial class SayHiControllerBase : ControllerBase
    {

        internal abstract ISayHi SayHiImpl { get; }

        ///<summary>
        /// say hello
        ///</summary>
        [HttpPost]
        [Route("/sayHi/hello")]
        [ProducesResponseType((int)HttpStatusCode.OK, Type = typeof(HelloContent))]
        public virtual async Task<IActionResult> Hello(HelloContent body)
        {
            var result = await SayHiImpl.HelloAsync(body);
            return Ok(result);
        }


        [HttpPost]
        [Route("/sayHi/world")]
        [ProducesResponseType((int)HttpStatusCode.OK, Type = typeof(WorldResult))]
        public virtual async Task<IActionResult> World()
        {
            var result = await SayHiImpl.WorldAsync();
            return Ok(result);
        }

    }
}

There are quite a few extra blank lines which produces warnings in the project.