Conductor Anna Handler, who grew up in Munich, is joining the renowned symphony orchestra in Boston. The 26-year-old will be assistant conductor there for two years from September, the Boston Symphony Orchestra announced on Thursday. The orchestra in the US East Coast metropolis has been led since 2014 by the Latvian star conductor Andris Nelsons, who is also Kapellmeister of the Leipzig Gewandhaus Orchestra. It is an “immense honor” for her to conduct the orchestra in Boston, Handler was quoted as saying in Opera Wire. “The storied history and unique sound of this orchestra fascinate me, and …