[tracker] Revert "meson: Don't require gobject-introspection"

[Sam Thursfield <sthursfield src gnome org>]

commit 515451eea93e1a4f022dda22fceaee7fb9611728
Author: Sam Thursfield <sam afuera me uk>
Date:   Sat Dec 16 14:43:03 2017 +0000

    Revert "meson: Don't require gobject-introspection"
    
    I should have tested this before merging! We do use this dependency.
    
    This reverts commit 4d963a2b95b7786324fb0932f7f73f0a926ea84b.

 meson.build |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/meson.build b/meson.build
index fa0e60b..36e0084 100644
--- a/meson.build
+++ b/meson.build
@@ -22,6 +22,7 @@ gio_unix = dependency('gio-unix-2.0', version: '>' + glib_required)
 glib = dependency('glib-2.0', version: '>' + glib_required)
 gmodule = dependency('gmodule-2.0', version: '>' + glib_required)
 gobject = dependency('gobject-2.0', version: '>' + glib_required)
+gobject_introspection = dependency('gobject-introspection-1.0')
 icu_i18n = dependency('icu-i18n', version: '> 4.8.1.1', required: false)
 icu_uc = dependency('icu-uc', version: '> 4.8.1.1', required: false)
 json_glib = dependency('json-glib-1.0', version: '>= 1.0', required: true)