Do not default to emacs if explicitly turned off (re: 1375cda9)

When a user invokes 'ksh +o emacs' they should not land in the
emacs line editor, as they explicitly asked not to have it. So
default to no editor mode in that case.

src/cmd/ksh93/sh/main.c

@@ -349,7 +349,7 @@ int sh_main(int ac, char *av[], Shinit_f userinit)
 #if SHOPT_VSH
 		&& !sh_isoption(SH_VI)
 #endif /* SHOPT_VSH */
-		)
+		&& !is_option(&sh.offoptions,SH_EMACS))
 			sh_onoption(SH_EMACS);
 #endif /* SHOPT_ESH */
 	}