Handle nil date for letter_head gracefully.
Handle nil date for letter_head gracefully.

hauledev/bookyt,silvermind/bookyt,huerlisi/bookyt,huerlisi/bookyt,hauledev/bookyt,silvermind/bookyt,wtag/bookyt,wtag/bookyt,gaapt/bookyt,hauledev/bookyt,xuewenfei/bookyt,gaapt/bookyt,gaapt/bookyt,silvermind/bookyt,huerlisi/bookyt,wtag/bookyt,xuewenfei/bookyt,silvermind/bookyt,hauledev/bookyt,xuewenfei/bookyt,gaapt/bookyt