README: fix when to run "conan install"

As pointed out on the forums.

README.md

@@ -86,8 +86,8 @@ Assuming that everything else has installed correctly, building Plex Media Playe
 * ``git clone git://github.com/plexinc/plex-media-player``
 * ``cd plex-media-player``
 * ``mkdir build``
-* ``conan install ..``
 * ``cd build``
+* ``conan install ..``
 * ``cmake -DCMAKE_BUILD_TYPE=Debug -DQTROOT=/opt/Qt5.6.1/5.6/gcc_64/ -DCMAKE_INSTALL_PREFIX=/usr/local/ ..``
 * ``make -j4``
 * ``sudo make install``