back port fix from JBSEAM-2292-Resources from resource servlet can't be re-rendered

Found this after using the captcha:

<div class="input">
<a:region>
<s:validateAll>
<h:graphicImage value="/seam/resource/captcha" style="vertical-align:text-bottom;"/>
<h:inputText tabindex="1" size="6" maxlength="6" required="true" id="verifyCaptcha" value="#

{captcha.response}">
<a:support status="#{statusId}" event="onblur" reRender="verifyCaptchaEntry"/>
</h:inputText>
</s:validateAll>
</a:region>
</div>

This is a re-rendered s:decorate form field, so that onblur we get a new challenge (if the captcha repsonse was wrong). However, the graphicImage is not reloaded from the server, the browser caches it. To prevent browser caching, this is a quick hack:

<div class="input">
<a:region>
<s:validateAll>
<h:graphicImage value="/seam/resource/captcha?nocache=#{wiki:generateRandomNumber()}" style="vertical-align:text-bottom;"/>
<h:inputText tabindex="1" size="6" maxlength="6" required="true" id="verifyCaptcha" value="#{captcha.response}

">
<a:support status="#

{statusId}

" event="onblur" reRender="verifyCaptchaEntry"/>
</h:inputText>
</s:validateAll>
</a:region>
</div>