[Fix] content type warning (#455)

* chore: release new version

* bump 0.10.2 -> 0.11.0

* refactor: better extract_subtype invalid type message and change log level

* chore: use warning log level

---------

Co-authored-by: Adriano Santos <adriano.santos@v3.com.br>

Author: sleipnir

lib/grpc/server/adapters/cowboy/handler.ex

@@ -649,7 +649,12 @@ defmodule GRPC.Server.Adapters.Cowboy.Handler do
   defp extract_subtype("application/grpc-web-text+" <> rest), do: {:ok, :grpcweb, rest}
 
   defp extract_subtype(type) do
-    Logger.warning("Got unknown content-type #{type}, please create an issue. ")
+    Logger.warning("""
+    Received invalid content-type: "#{type}".
+    This usually means the request is missing a proper Content-Type header,
+    or it's using a non-standard value. This may cause request parsing or response
+    encoding errors.
+    """)
 
     {:ok, :unknown, "unknown"}
   end