bootstrap1: .org directive is useless in a case of binary output

so we may remove one.

Thank you @slo

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>

Booting/linux-bootstrap-1.md

@@ -110,7 +110,6 @@ For example:
 ; Note: this example is written in Intel Assembly syntax
 ;
 [BITS 16]
-[ORG  0x7c00]
 
 boot:
     mov al, '!'