add /favicon.ico to satisfy 3rd party libraries
add /favicon.ico to satisfy 3rd party libraries

(cherry picked from commit a8d1c15)

sillsdev/web-cat,sillsdev/web-cat,sillsdev/web-cat,ermshiperete/web-languageforge,sillsdev/web-cat,sillsdev/web-scriptureforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,ermshiperete/web-languageforge,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,sillsdev/web-cat,ermshiperete/web-languageforge,sillsdev/web-cat,ermshiperete/web-languageforge,sillsdev/web-scriptureforge,sillsdev/web-cat,sillsdev/web-scriptureforge,sillsdev/web-scriptureforge,sillsdev/web-cat