osx: remove workaround for recent Xcode versions

docs/index.html

@@ -854,16 +854,6 @@ USE_OSGPLUGIN(<plugin2>)
     </p>
     <p>
     <h5>Certain packages have open issues on OS X</h5>
-    </p>
-    <p>
-    For Xcode ≥ 8.3 install an alternate compiler to build `gcc`.
-    For example, if you use Macports run:
-    <pre>sudo port install gcc5
-make cmake && \
-sudo port select gcc mp-gcc5 && \
-make gcc -j4 && \
-sudo port select gcc none && \
-make -j4 -k</pre>
     </p>
     <p>
     For Xcode <7.3, run: