Rainfall history tile creation crashes if option is turned off

[xcguy]

When the option "Create a 7-Day Rain History Tile" (var: rainhistory) is turned off, the refresh code in 'rainTile' will crash with:
org.codehaus.groovy.runtime.typehandling.GroovyCastException: Cannot cast object 'null' with class 'null' to class 'int'. Try 'java.lang.Integer' instead
This crash can have a cascading effect, as the polling code is executed during an update, and thus causes the poll scheduling (and auto log info off feature) to not be programmed. This effectively breaks the driver, as no weather updates will be requested.