fix(api): Prepare request fix

Author: goodpaul6

src/postgrid/_client.py

@@ -121,7 +121,7 @@ def _prepare_request(
         request: httpx.Request,  # noqa: ARG002
     ) -> None:
         # Update API key header based on URL of request
-        if 'print-mail' in request.url:
+        if 'print-mail' in request.url.path:
             request.headers['x-api-key'] = self.print_mail_api_key
         else:
             request.headers['x-api-key'] = self.address_verification_api_key
@@ -341,7 +341,7 @@ async def _prepare_request(
         request: httpx.Request,  # noqa: ARG002
     ) -> None:
         # Update API key header based on URL of request
-        if 'print-mail' in request.url:
+        if 'print-mail' in request.url.path:
             request.headers['x-api-key'] = self.print_mail_api_key
         else:
             request.headers['x-api-key'] = self.address_verification_api_key