- Clean-up %arm build

- update to Firefox 63.0.3
* Games using WebGL (created in Unity) get stuck after very short
time of gameplay (bmo#1502748)
* Slow page loading for some users with specific proxy configurations
(bmo#1495024)
* Disable HTTP response throttling by default for causing bugs with
videos in background tabs (bmo#1503354)
* Opening magnet links no longer works (bmo#1498934)
* Crash fixes (bmo#1498510, bmo#1503424)
- removed mozilla-newer-cbindgen.patch; no longer needed

- update to Firefox 63.0.1
* Snippets are not loaded due to missing element (bmo#1503047)
* Print preview always shows 30& scale when it is actually
Shrink To Fit (bmo#1501952)
* Dialog displayed when closing multiple windows shows unreplaced
%1$S placeholder in Japanese and potentially other locales
(bmo#1500823)

- update to Firefox 63.0
* WebExtensions now run in their own process on Linux
* The Ctrl+Tab shortcut now displays thumbnail previews of your
tabs and cycles through tabs in recently used order. This new
default behavior is activated only in new profiles and can be
changed in preferences.
* Added support for Web Components custom elements and shadow DOM
MFSA 2018-26 (bsc#1112852)
* CVE-2018-12391 (bmo#1478843) (Android-only)