title: Validation error with integer property (camel)
body: <p>I'am using OSGi Configuration Properties in Blueprint Camel (v 2.13.2) and everything was fine until I tried to properties a integer property : timePeriodMillis in  tag.</p>
  
  <p>This code works nice :</p>
  
  <pre><code>&lt;blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cxf="http://camel.apache.org/schema/blueprint/cxf" xmlns:cm="http://aries.apache.org/blueprint/xmlns/blueprint-cm/v1.1.0"
  xsi:schemaLocation="
           http://www.osgi.org/xmlns/blueprint/v1.0.0 http://www.osgi.org/xmlns/blueprint/v1.0.0/blueprint.xsd
           http://camel.apache.org/schema/blueprint http://camel.apache.org/schema/blueprint/camel-blueprint.xsd"&gt;
  
  
      &lt;cm:property-placeholder persistent-id="myprops"/&gt;
  
      &lt;camelContext  xmlns="http://camel.apache.org/schema/blueprint"&gt;
  
          &lt;route id="rt" trace="false" autoStartup="false"&gt;
              &lt;from uri="amq://{{myQueue}}"/&gt;
              &lt;throttle timePeriodMillis="5"&gt;
                  &lt;constant&gt;{{maxRPP}}&lt;/constant&gt;
                  &lt;to uri="direct:mock" /&gt;
              &lt;/throttle&gt;
          &lt;/route&gt;    
      &lt;/camelContext&gt;
  &lt;/blueprint&gt;
  </code></pre>
  
  <p>When I properties timePeriodMillis : </p>
  
  <pre><code>&lt;throttle timePeriodMillis="{{timePM}}"&gt;
  </code></pre>
  
  <p>I got two validation errors : </p>
  
  <pre><code>cvc-attribute.3: The value '{{timePM}}' of attribute 'timePeriodMillis' on element 'throttle' is not valid with respect to its type, 'long'.
  cvc-datatype-valid.1.2.1: '{{timePM}}' is not a valid value for 'integer'.
  </code></pre>
  
  <p>When I change it to (no quote) : </p>
  
  <pre><code>&lt;throttle timePeriodMillis={{timePM}}&gt;  
  </code></pre>
  
  <p>I got again a validation error : </p>
  
  <pre><code>Open quote is expected for attribute "timePeriodMillis" associated with an  element type  "throttle".
  </code></pre>
  
  <p>Any idea ? Thanks</p>