Fix example in fft plugin
Fix example in fft plugin

kyroskoh/dancer.js,modulexcite/dancer.js,jsantell/dancer.js,modulexcite/dancer.js,ngokevin/dancer.js,suryasingh/dancer.js,ngokevin/dancer.js,suryasingh/dancer.js,hoboman313/dancer.js,hoboman313/dancer.js,kyroskoh/dancer.js