Add space after numeric value on second line of DOORFILE.SR

This appears to work around a bug in BRE, FE, and TAL where they don't
recognize the "1" (ANSI supported) unless there is at least one other
character on the line following the decimal digit, resulting in the
unnecessary prompting of the user:
  This game is much more enjoyable with ANSI graphics enabled.
  Do you want ANSI Graphics? (Y/n)

As reported by "ben" in IRC.