Fix mistyped "extraOptions"

I234e888752526475f4c72da7479023fcd14a1ee9 added a regression by mistyping
"extraOptions" as "extraConfig". This commit fixes the option name

Change-Id: I043028e7c6f26b4868fb8e6a7230809b966c8f27
diff --git a/modules/nextcloud.nix b/modules/nextcloud.nix
index 0dc27bc..8574407 100644
--- a/modules/nextcloud.nix
+++ b/modules/nextcloud.nix
@@ -38,7 +38,7 @@
         extraTrustedDomains = [ "nextcloud.clicks.codes" "docs.clicks.codes" ];
     };
 
-    services.nextcloud.extraConfig = {
+    services.nextcloud.extraOptions = {
         social_login_auto_redirect = true;
     };