title: failed to set property into delayer
body: <p>I faced a problem, when I use this spring-camel context I got error about type conversion from String to Long, related to second {{retryCount}}. When I start debugging I realised that BaseTypeConverterRegistry#convertTo method got retryCount value (let say 10) in the first occurence and value "{{retryCount}}" in the second case (delayer component), so I don't know why.</p>
  
  <p>My Spring Camel context:</p>
  
  <pre><code>&lt;propertyPlaceholder location="classpath:camel.properties" id="properties" /&gt;
    &lt;route id="mojorun"&gt;
      &lt;from uri="timer://runOnce?delay=0&amp;amp;repeatCount=1" /&gt;
      &lt;loop&gt;
        &lt;spring:constant&gt;{{retryCount}}&lt;/spring:constant&gt;
        &lt;spring:inOnly uri="bean:mojo?method=shout"/&gt;
        &lt;spring:delay&gt;
          &lt;spring:constant&gt;{{retryCount}}&lt;/spring:constant&gt;
        &lt;/spring:delay&gt;
      &lt;/loop&gt;
    &lt;/route&gt;
  </code></pre>