Get web view's URL at runtime

If a Turbo request is redirected to a page with a Strada component this
check would always fail. `location` is only set when `BridgeDelegate` is
initialized. This change dynamically grabs the URL from the web view,
falling back to the original `location` if nil.

Fixes #23

Source/BridgeDelegate.swift

@@ -117,7 +117,7 @@ public final class BridgeDelegate: BridgingDelegate {
     @discardableResult
     public func bridgeDidReceiveMessage(_ message: Message) -> Bool {
         guard destinationIsActive,
-              location == message.metadata?.url else {
+              webView?.url?.absoluteString ?? location == message.metadata?.url else {
             logger.warning("bridgeDidIgnoreMessage: \(String(describing: message))")
             return false
         }