Force evaluation of reverse_lazy urls in set_query_parameters. Fixes #…

…1311

Passing reverse_lazy url to SpectacularRedocView errors because set_query_parameters calls urlls.parse.urlparse on url which may not be a string but a 'django.utils.functional.lazy.<locals>.__proxy__'. Forcing url to be string fixes this issue.

drf_spectacular/plumbing.py

@@ -1280,6 +1280,7 @@ def build_mock_request(method, path, view, original_request, **kwargs):
 
 def set_query_parameters(url, **kwargs) -> str:
     """ deconstruct url, safely attach query parameters in kwargs, and serialize again """
+    url = str(url) # Force evaluation of reverse_lazy urls
     scheme, netloc, path, params, query, fragment = urllib.parse.urlparse(url)
     query = urllib.parse.parse_qs(query)
     query.update({k: v for k, v in kwargs.items() if v is not None})