Change help text for -p option
Change help text for -p option

It says teh default is vanilla, but the default is
really all plugins

Closes-Bug: #1373585
Change-Id: Ic3f4ae862729c734dff6c11f739f640e36072df4

crobby/sahara-image-elements,uladz/sahara-image-elements,bigfootproject/sahara-image-elements,openstack/sahara-image-elements,bigfootproject/sahara-image-elements,uladz/sahara-image-elements,crobby/sahara-image-elements,openstack/sahara-image-elements