fix: use a valid module name

Author: sleipnir

lib/sidecar/grpc/generators/handler_transcoding_generator.ex

@@ -50,15 +50,15 @@ defmodule Sidecar.GRPC.Generators.HandlerTranscodingGenerator do
       {"unknown",
        [
          render: false,
-         module: "unknown"
+         module: "Unknown"
        ]}
 
   defp do_generate(_ctx, []),
     do:
       {"unknown",
        [
          render: false,
-         module: "unknown"
+         module: "Unknown"
        ]}
 
   defp do_generate(ctx, svcs) do