refactor(uri): replace single string with character

Author: tottoto

src/uri/authority.rs

@@ -238,7 +238,7 @@ impl Authority {
     pub fn port(&self) -> Option<Port<&str>> {
         let bytes = self.as_str();
         bytes
-            .rfind(":")
+            .rfind(':')
             .and_then(|i| Port::from_str(&bytes[i + 1..]).ok())
     }