[CentOS-docs] Clarification in HowTos/MigrationGuide page

[Alain Reguera Delgado]

Hi,

A little more of clarification :) ... In some wiki pages say that the
protectbase and priorities yum plugins can not be used together. It
seems that the next paragraph must be updated:

====>
Always beware when using/mixing 3rd-party repos. The yum protectbase
and/or priorities plugins are your friends. Although both can be used
together, using protectbase is probably unnecessary if priorities are
configured properly. See
Using_protectbase_and_fastestmirror_yum_plugins and
yum-plugin-priorities.
<====

See where it says --- Although both can be used together --- .

Other things to note here are:
  - the link to yum-plugin-priorities page has no information, maybe
it could be pointed to PackageManagement/Yum/Priorities page.
  - the large Using_protectbase_and_fastestmirror_yum_plugins link
maybe could be replaced by two small links to the corresponding plugin
pages or just the yum's wiki page ?

What do you think ?

Thanks guys,

al.