help: remove extra blank line after "See 'git --help'" message

The double LF were there only because we gave a list of common
commands.  WIth the list gone, there is no reason to have the
extra blank line.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

help.c

@@ -185,7 +185,7 @@ static void show_man_page(const char *git_cmd)
 
 void help_unknown_cmd(const char *cmd)
 {
-	fprintf(stderr, "git: '%s' is not a git-command. See --help\n\n", cmd);
+	fprintf(stderr, "git: '%s' is not a git-command. See 'git --help'.\n", cmd);
 	exit(1);
 }