cvs: initialize empty password

If we do not read a password from the command line, and there are no
passwords stored in .cvspass, we have to initialize the password with
just "A".

This fixes a regression introduced by 3fb9d582 (Do not scramble
password read from .cvspass).

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-cvsimport.perl

@@ -253,6 +253,7 @@ sub conn {
 					}
 				}
 			};
+			$pass = "A" unless $pass;
 		}
 
 		my ($s, $rep);