CBQE-2144: Increase retries to connect build url during installation

Change-Id: Ic0be6345c8d352e97a5aacfc32bcb1de475e08f1
Reviewed-on: http://review.couchbase.org/34837
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>