wrong example misguide user to catch panic (#414)

Signed-off-by: wander1024 <yawhua1024@gmail.com>

README.md

@@ -29,20 +29,20 @@ import "github.com/grpc-ecosystem/go-grpc-middleware"
 
 myServer := grpc.NewServer(
     grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
+        grpc_recovery.StreamServerInterceptor(),
         grpc_ctxtags.StreamServerInterceptor(),
         grpc_opentracing.StreamServerInterceptor(),
         grpc_prometheus.StreamServerInterceptor,
         grpc_zap.StreamServerInterceptor(zapLogger),
         grpc_auth.StreamServerInterceptor(myAuthFunction),
-        grpc_recovery.StreamServerInterceptor(),
     )),
     grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
+        grpc_recovery.UnaryServerInterceptor(),
         grpc_ctxtags.UnaryServerInterceptor(),
         grpc_opentracing.UnaryServerInterceptor(),
         grpc_prometheus.UnaryServerInterceptor,
         grpc_zap.UnaryServerInterceptor(zapLogger),
         grpc_auth.UnaryServerInterceptor(myAuthFunction),
-        grpc_recovery.UnaryServerInterceptor(),
     )),
 )
 ```