Update format of 4.2.0 upgrade commands
Update format of 4.2.0 upgrade commands

Make Ubuntu and CentOS commands consistently formatted ( $ sudo ... ) for 4.2.0 upgrade instructions.

Signed-off-by: Sebastien Goasguen <250735a416ca4fba2eb297c8d62b7a634570c133@gmail.com>

apache/cloudstack-docs-rn,remibergsma/cloudstack-docs-rn,remibergsma/cloudstack-docs-rn,apache/cloudstack-docs-rn,apache/cloudstack-docs-rn,remibergsma/cloudstack-docs-rn