gstreamer1: remove libunwind support.

Pretty printing backtraces isn't extremely useful most of the time and
can be done in a much better way via a proper debugger. Furthermore, and
the motivation for this, having libunwind in gstreamer1 leads to gtkd
being linked against two libunwind impls, one via gstreamer1 (libunwind)
and the other via ldc-runtime (llvm-libunwind).

srcpkgs/gstreamer1/template

@@ -1,7 +1,7 @@
 # Template file for 'gstreamer1'
 pkgname=gstreamer1
 version=1.18.4
-revision=1
+revision=2
 wrksrc="gstreamer-${version}"
 build_style=meson
 build_helper="gir"
@@ -10,7 +10,7 @@ configure_args="-Dptp-helper-permissions=capabilities
  -Dintrospection=$(vopt_if gir enabled disabled)"
 hostmakedepends="gettext pkg-config flex python3 docbook-xsl glib-devel
  libcap-progs"
-makedepends="libxml2-devel libglib-devel gtk+3-devel libcap-devel libunwind-devel
+makedepends="libxml2-devel libglib-devel gtk+3-devel libcap-devel
  bash-completion"
 checkdepends="gsl-devel gmp-devel valgrind-devel"
 short_desc="Core GStreamer libraries and elements (1.x)"