chore: simplify allowlist check

Author: jawabuu

oidc/views.py

@@ -55,7 +55,7 @@ def dispatch(self, request, helper):
         if domain in OIDC_DOMAIN_BLOCKLIST:
             return helper.error(ERR_INVALID_DOMAIN % (domain,))
 
-        if OIDC_DOMAIN_ALLOWLIST != set() and domain not in OIDC_DOMAIN_ALLOWLIST:
+        if OIDC_DOMAIN_ALLOWLIST and domain not in OIDC_DOMAIN_ALLOWLIST:
             return helper.error(ERR_INVALID_DOMAIN % (domain,))
 
         helper.bind_state("domain", domain)