message: refactor(uri): Add default path for absolute-form
  Add default path ("/") for absolute-form, even if not included.
  This change assumes self.scheme().is_some() indicates that the Uri
  is in absolute-form.
  Issue:
diff: @@ -88,6 +88,9 @@ impl Uri {
  let end = self.source.len() - if query_len > 0 { query_len + 1 } else { 0 } -
  if fragment_len > 0 { fragment_len + 1 } else { 0 };
  if index >= end {
  + if self.scheme().is_some() {
  + return "/" // absolute-form MUST have path
  + }
  ""
  } else {
  &self.source[index..end]
  @@ -317,7 +320,7 @@ test_parse! {
  "http://127.0.0.1:80",
  scheme = Some("http"),
  - authority = Some("127.0.0.1"),
  + authority = Some("127.0.0.1:80"),
  path = "/",
  query = None,
  fragment = None,
  @@ -328,7 +331,7 @@ test_parse! {
  "https://127.0.0.1:443",
  scheme = Some("https"),
  - authority = Some("127.0.0.1"),
  + authority = Some("127.0.0.1:443"),
  path = "/",
  query = None,
  fragment = None,
  