title: Lua gsub second instance
body: <p>I'm using</p>
  
  <pre><code>local mystring = 'Thats a really nice house.'
  string.gsub(mystring,"% ", "/",1)
  </code></pre>
  
  <p>to replace the first white space character with an slash.</p>
  
  <p>But how to replace only the second occurrence of the white space?</p>