Fixed #36734 again.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@36779 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/resources/hudson/triggers/SCMTrigger/global.jelly

@@ -32,6 +32,7 @@ THE SOFTWARE.
       <f:entry title="${%Max # of concurrent polling}"
                help="/help/triggers/SCMTrigger/concurrency.html">
         <f:textbox name="poll_scm_threads"
+          checkUrl="'descriptorByName/SCMTrigger/checkPoll_scm_threads?value='+encodeURIComponent(this.value)"
           value="${descriptor.pollingThreadCount==0 ? '' : descriptor.pollingThreadCount}"/>
       </f:entry>
     </f:section>