Empty memorysession when route  contains path params
Hey there I found an issue with the memorysession. When a route has a path parameter sessions is not immediately updated after the route is processed. Using the memorysession example in the [repo](https://github.com/planety/prologue/tree/devel/examples/memorysession) add the route `login/{id}` as shown below

```nim

# urls.nim

import prologue

import ./views


const urlPatterns* = @[
  pattern("/", hello),
  pattern("/login/", login),
  pattern("/login/{id}", login),
  pattern("/logout", logout),
  pattern("/print", print)
]
```

 Update the `login` handler to actually use  the path parameter like so

```nim

# view.nim

import prologue

proc hello*(ctx: Context) {.async.} =
  resp "<h1>Hello, Prologue!</h1>"

proc login*(ctx: Context) {.async.} =
  ctx.session["flywind"] = "123"
  ctx.session["ordontfly"] = "345"

  ## Be careful when using session or csrf middlewares,
  ## Response object will cover the headers of before.
  resp htmlResponse("<h1>Login</h1>" & $ctx.getPathParams("id"), headers = ctx.response.headers)

proc print*(ctx: Context) {.async.} =
  resp $ctx.session

proc logout*(ctx: Context) {.async.} =
  ctx.session.clear()
  resp htmlResponse("<h1>Logout</h1>", headers = ctx.response.headers)
```

Now when you run the app  and now call `http://localhost:8080/login/1` and  then check `http://localhost:8080/print` as before you will see session is empty. 

Route `http://localhost:8080/login` works just fine as before


