fix(aur): Add sphinx as a build dependency

contrib/polybar.aur/PKGBUILD

@@ -2,7 +2,7 @@
 # Contributor: Michael Carlberg <c@rlberg.se>
 pkgname=polybar
 pkgver=3.4.0
-pkgrel=1
+pkgrel=4
 pkgdesc="A fast and easy-to-use status bar"
 arch=("i686" "x86_64")
 url="https://github.com/polybar/polybar"
@@ -13,7 +13,8 @@ optdepends=("i3-wm: i3 module support"
             "ttf-unifont: Font used in example config"
             "siji-git: Font used in example config"
             "xorg-fonts-misc: Font used in example config")
-makedepends=("cmake" "git" "python" "python2" "pkg-config" "i3-wm")
+makedepends=("cmake" "git" "python" "python2" "pkg-config" "python-sphinx"
+             "i3-wm")
 conflicts=("polybar-git")
 install="${pkgname}.install"
 source=(${url}/releases/download/${pkgver}/polybar-${pkgver}.tar)