tdf#111988 Bump OSX version in README

Change-Id: I41a5be165af21c197c4f9d4f40f0ff27c80a7168
Reviewed-on: https://gerrit.libreoffice.org/55061Reviewed-by: Sophia Schröder <sophia.schroeder@libreoffice.org>
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>

readlicense_oo/docs/readme.xrm

@@ -34,7 +34,7 @@
 			<div class="MAC" id="SystemRequirements_OSX">
 				<ul>
 					<li>
-						<p id="macxiOSX" xml:lang="en-US">MacOSX 10.8 (Mountain Lion) or higher</p>
+						<p id="macxiOSX" xml:lang="en-US">MacOSX 10.9 (Mavericks) or higher</p>
 					</li>
 				</ul>
 			</div>