Prevent out of bounds check on the password method

Author: o0Ignition0o

src/lib.rs

@@ -752,7 +752,10 @@ impl Url {
     pub fn password(&self) -> Option<&str> {
         // This ':' is not the one marking a port number since a host can not be empty.
         // (Except for file: URLs, which do not have port numbers.)
-        if self.has_authority() && self.byte_at(self.username_end) == b':' {
+        if self.has_authority()
+            && self.username_end < self.serialization.len() as u32
+            && self.byte_at(self.username_end) == b':'
+        {
             debug_assert!(self.byte_at(self.host_start - 1) == b'@');
             Some(self.slice(self.username_end + 1..self.host_start - 1))
         } else {