remove almost-duplicate menu item for Evolution

[Roman Polach]

According to https://answers.launchpad.net/ubuntu/+source/evolution/+question/9119 information
the reason of duplicate Evolution menu entry is that Internet->Evolution Mail launches mail component always,
but Office->Evolution launches last component used.

I thing one of these items should be removed.
The reasons are:
 * when user uses Evolution Mail for most time (and most desktop users will do so), the last used component would be Mail anyway
 * it confuses users... the most of users recognize Evolution as Mail client with additions (not a set of equal components)... users simply want to "run a mail client"
 * "Evolution" and "Evolution Mail" looks like synonyms to user... most of users use short names of applications... they say "GIMP", not "GIMP Image Editor", etc...
   so "Evolution" means "Evolution Mail" for most...
 * switching to another component is very easy inside Evolution itself, there is no need to have 2 items in menu... The situation here is equivalent to e.g. if Brasero
   burning application have one launcher in "Sound and Video" menu to run cd-audio-burning-component and another in "Accessories" menu to run its data-cd-burning-component
 * When users found that Evolution has two menu items that seems to behave the same way, they may ask stupid questions in Launchpad... like me ;-)

[Sebastien Bacher (seb128)]

Thanks for the bug report. This particular bug has already been reported, but feel free to report any other bugs you find.