A Chelsea man who earned the nickname “Spelling Bee Bandit” after robbing four Boston-area banks by passing the teller a note with the word robbery misspelled was sentenced to seven years behind bars yesterday, officials said.Jason S. Englen, 34, was sentenced in U.S. District Court in Boston to seven years in prison followed by three years of supervised release, U.S. Attorney Andrew E. Lelling’s office announced. Englen pleaded guilty last year to four counts of bank robbery and had been facing 20 years in jail.