ardour: update to 5.12.

Closes: #11291 [via git-merge-pr]

srcpkgs/ardour/template

@@ -1,9 +1,9 @@
 # Template file for 'ardour'
 pkgname=ardour
-version=5.9
+version=5.12
 revision=1
 build_style=waf
-configure_args="--with-backends=jack,alsa --libjack=weak --optimize --docs"
+configure_args="--cxx11 --no-phone-home --with-backends=jack,alsa --libjack=weak --optimize --docs"
 hostmakedepends="python git graphviz doxygen pkg-config clang perl"
 makedepends="boost-devel liblrdf-devel liblo-devel lilv-devel suil-devel
  taglib-devel aubio-devel rubberband-devel alsa-lib-devel libsndfile-devel
@@ -13,7 +13,6 @@ short_desc="Professional-grade digital audio workstation"
 maintainer="Andrea Brancaleoni <abc@pompel.me>"
 license="GPL-2"
 homepage="http://ardour.org"
-CXXFLAGS="-std=c++11"
 
 nocross="executes test binaries during configure"