build: Update gvc to support renamed options

gvc has made some recent changes that rename its user options
following meson guidelines for GNOME packages[0].

The options used in gvc as a subproject have been renamed
accordingly.

[0] https://wiki.gnome.org/Initiatives/GnomeGoals/MesonPorting

meson.build

@@ -167,12 +167,12 @@ conf_inc = include_directories('.')
 
 libgvc = subproject('gvc',
   default_options: [
-    'package-name=' + meson.project_name(),
-    'package-version=' + meson.project_version(),
+    'package_name=' + meson.project_name(),
+    'package_version=' + meson.project_version(),
     'pkgdatadir=' + pkgdatadir,
     'pkglibdir=' + pkglibdir,
     'static=false',
-    'with-introspection=true',
+    'introspection=true',
     'alsa=false'
   ]
 )

subprojects/gvc

@@ -1 +1 @@
-Subproject commit 67533bffdcd22893b28baa411b2e75bd75dce323
+Subproject commit 6a0ac9ba69f84d763f286c5741b57ff8d87c1f45