Don't let TokenError bubble up from lib2to3_parse (GH-2343)

error: cannot format <string>: ('EOF in multi-line statement', (2, 0))
   
 ▲ before ▼ after

error: cannot format <string>: Cannot parse: 2:0: EOF in multi-line statement

Co-authored-by: Richard Si <63936253+ichard26@users.noreply.github.com>