NEWS: fix empty lines

Make sure there are exactly two empty lines between different versions
(rather than 1 or 3).

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Balazs Lecz <leczb@google.com>

NEWS

@@ -8,6 +8,7 @@ Version 2.1.2.1
 
 Fix a bug which prevented untagged KVM instances from starting.
 
+
 Version 2.1.2
 -------------
 
@@ -105,7 +106,6 @@ etc. Among others:
   connected client
 
 
-
 Version 2.1.1
 -------------