ReservedFontName-check: change into warning and improve wording
ReservedFontName-check: change into warning and improve wording

(issue #1163)

moyogo/fontbakery,googlefonts/fontbakery,graphicore/fontbakery,googlefonts/fontbakery,graphicore/fontbakery,graphicore/fontbakery,moyogo/fontbakery,googlefonts/fontbakery,moyogo/fontbakery