firefox-extension-*: hardcode id's

These id's will probably never change.

.SRCINFO

@@ -1,11 +1,10 @@
 pkgbase = firefox-extension-stylish
 	pkgdesc = Restyle the web with Stylish, a user styles manager.
 	pkgver = 2.0.1
-	pkgrel = 1
+	pkgrel = 2
 	url = https://userstyles.org
 	arch = any
 	license = GPL3
-	makedepends = python
 	depends = firefox
 	source = https://addons.cdn.mozilla.net/user-media/addons/2108/stylish-2.0.1-an+tb+sm+fx.xpi
 	sha256sums = f3770e9b6479f0b14dee59c806c93c615b3fa8858121fa1a6cd7c9d3d1cf26c1

PKGBUILD

@@ -2,24 +2,18 @@
 
 pkgname=firefox-extension-stylish
 pkgver=2.0.1
-pkgrel=1
+pkgrel=2
 pkgdesc='Restyle the web with Stylish, a user styles manager.'
 url=https://userstyles.org
 arch=('any')
 license=('GPL3')
 depends=('firefox')
-makedepends=('python')
 source=("https://addons.cdn.mozilla.net/user-media/addons/2108/stylish-$pkgver-an+tb+sm+fx.xpi")
 sha256sums=('f3770e9b6479f0b14dee59c806c93c615b3fa8858121fa1a6cd7c9d3d1cf26c1')
 
 package() {
   local GLOBIGNORE=*.xpi:COPYING
-  local emid=$(python -c \
-"import xml.etree.ElementTree as ET
-tree = ET.parse('install.rdf')
-root = tree.getroot()
-print(root[0][0].text)")
-  local dstdir="$pkgdir"/usr/lib/firefox/browser/extensions/"$emid"
+  local dstdir="$pkgdir"/usr/lib/firefox/browser/extensions/"{46551EC9-40F0-4e47-8E18-8E5CF550CFB8}"
 
   install -d "$dstdir"
   cp -r * "$dstdir"