HELSINKI (Reuters) - Finland's central bank cut its growth forecast to 1.3 % for this year on Tuesday, from a previous estimate of 1.6 % in July, blaming sluggishness in the global economy.It also forecast gross domestic product to grow 0.9% for 2020 and 1.1% for 2021, compared with previous estimates of 1.5% and 1.3% respectively.Finland's economy grew at 1.7% in 2018, according to Statistics Finland."Finland's economic boom is over and growth is temporarily losing momentum amid weaker global..