test build wtp4x only once per day

releng.control/cc_config.xml

@@ -838,7 +838,7 @@
                 reallyquiet="${env.CVS_QUIET}"/>
         </modificationset>
         <schedule
-            interval="${time.fourHours}">
+            interval="${time.twentyFourHours}">
             <ant
                 antscript="${env.RELENG_CONTROL}/ant_low_priority.sh">
                 <property