Updated Windows installation instructions

doc/install.windows

@@ -30,7 +30,7 @@ The MSYS2 project does not provide a package for libvncclient, and since our
 needs are pretty specific, we provide the source to build a package which just
 install the client side VNC libraries.
 
-* Install dependencies: pacman -S pkgconf
+* Install dependencies: pacman -S mingw-w64-i686-pkgconf patch
 * Get the package code: darcs get http://devel.ag-projects.com/repositories/windows/mingw-w64-libvncclient
 * Enter the directory and build the package: cd mingw-w64-libvncclient && makepkg-mingw -L --nocheck
 * In case the above command fails with an error regarding a non-existent icon file,