[FAB-13282] Clarify version of node.js

The current wording in the prerequisite document is unclear with regards to
which version of node.js is required.

Change-Id: I2529ad712d7f4f3a371967fe37e1e5198d2a1614
Signed-off-by: Alessandro Sorniotti <ale.linux@sopit.net>
(cherry picked from commit 5298e23)

docs/source/prereqs.rst

@@ -100,9 +100,9 @@ If you will be developing applications for Hyperledger Fabric leveraging the
 Hyperledger Fabric SDK for Node.js, you will need to have version 8.9.x of Node.js
 installed.
 
-.. note:: Node.js version 9.x is not supported at this time.
+.. note:: Versions other than the 8.x series are not supported at this time.
 
-  - `Node.js <https://nodejs.org/en/download/>`__ - version 8.9.x or greater
+  - `Node.js <https://nodejs.org/en/download/>`__ - version 8.x
 
 .. note:: Installing Node.js will also install NPM, however it is recommended
           that you confirm the version of NPM installed. You can upgrade