Increase read and sort buffers on nextcloud

modules/nextcloud/default.nix

@@ -22,6 +22,8 @@ in
     mysqld = {
       innodb_file_per_table = 1;
       innodb_buffer_pool_size = "2G";
+      read_rnd_buffer_size = "4M";
+      sort_buffer_size = "4M";
     };
   };