roles/nextcloud: fix reverse proxy for webdav

roles/nextcloud/templates/nextcloud.conf.j2

@@ -17,10 +17,10 @@ location = /robots.txt {
 }
 
 location = /.well-known/carddav {
-    return 301 $scheme://$host:$server_port/remote.php/dav;
+    return 301 $scheme://$host/remote.php/dav;
 }
 location = /.well-known/caldav {
-    return 301 $scheme://$host:$server_port/remote.php/dav;
+    return 301 $scheme://$host/remote.php/dav;
 }
 
 # set max upload size