Fixed NullPointerException when Matrix is printed at sbt console
Fixed NullPointerException when Matrix is printed at sbt console

Signed-off-by: Gustavo Salazar Torres <4c835a403594c701c802d13c2e4160025b081e70@gmail.com>

claydonkey/breeze,ContentSquare/breeze,mredaelli/breeze,nikdon/breeze,wstcpyt/breeze,chen0031/breeze,sheide/breeze,calippo/breeze,crealytics/breeze,cilier/breeze,scalanlp/breeze