Bail out of onResize if the menu is closed.
Bail out of onResize if the menu is closed.

This takes care of the errant TypeError caused by trying to find the
dimensions of a DOM element that doesn't exist.

https://seedscientific.atlassian.net/browse/POLIO-547

SeedScientific/polio,unicef/polio,SeedScientific/polio,unicef/rhizome,SeedScientific/polio,unicef/polio,SeedScientific/polio,SeedScientific/polio,unicef/rhizome,unicef/polio,unicef/polio,unicef/rhizome,unicef/rhizome