title: Postgresql error 53300 even though there are fewer connections than maximum allowed
body: <p>I'm using <code>npgsql</code> on my ASP.NET application to connect to a postgres database. On trying to open a connection, I get the following error: <code>53300: remaining connection slots are reserved for non-replication superuser connections</code>.</p>
  <p>Now, the maximum number of connections is set to 100 (verified with <code>SHOW max_connections;</code>) and currently, there are only 6 connections that are active (as returned by <code>select count(*) from pg_stat_activity;</code>).</p>
  <p>I have tried restarting postgres without any luck.</p>
  <p>Why am I getting the 53300 error?</p>