Nominate Alessandro Sorniotti as maintainer

Alessandro has been the key contributor on MSP/crypto components
and a security expert on the team. He has also worked on many
other components, from design, code to reviews, especially
with security focus. He has presented Fabric at numerous venues,
from industry to academic events to promote Hyperledger and
Hyperledger Fabric.

Currently we have no maintainers from MSP/crypto components.

The above was copied from Alessandro's nomination from a year
ago. There were not enough votes cast last year due to
multiple inactive maintainers at the time. Since that time,
Alessandro has been working in a virtual maintainer role, but
without the title. For example Alessandro has led critical
new features such as state-based endorsement and is re-designing
the validation code to support the next generation of Fabric
capabilities. Over the last year, Alessandro has been a mentor
and expert code reviewer to many community members across many CRs.
Now that the inactive maintainers have retired, it's time
to bring the nomination to another vote.

Change-Id: Icaae2682f2a74025fb7a586481901637e2f06d50
Signed-off-by: David Enyeart <enyeart@us.ibm.com>

Author: denyeart

docs/source/MAINTAINERS.rst

@@ -6,6 +6,8 @@ Maintainers
 +---------------------------+---------------------+------------------+----------------+-------------------------------------+
 | Name                      | Gerrit              | GitHub           | Chat           | email                               |
 +===========================+=====================+==================+================+=====================================+
+| Alessandro Sorniotti      | ale-linux           | ale-linux        | aso            | ale.linux@sopit.net                 |
++---------------------------+---------------------+------------------+----------------+-------------------------------------+
 | Artem Barger              | c0rwin              | c0rwin           | c0rwin         | bartem@il.ibm.com                   |
 +---------------------------+---------------------+------------------+----------------+-------------------------------------+
 | Binh Nguyen               | binhn               | binhn            | binhn          | binh1010010110@gmail.com            |