Log Message:
ibus, ibus-python: update to 1.5.21.

pkgsrc changes:
 - pull upstream fixes (will appear in the next version):
  - bus: Implement GDBusAuthObserver callback (to avoid #2116 conflicts)
    https://github.com/ibus/ibus/commit/3d442dbf936d197aa11ca0a71663c2bc61696151
  - g_dbus_server_new_sync() is failed with address unix:tmpdir=/tmp/ibus
    https://github.com/ibus/ibus/issues/2116
  - Save address file in XDG_RUNTIME_DIR
    https://github.com/ibus/ibus/pull/2128
 - explicitly pull Unicode 12.0 packages to avoid unexpected inconsistency
 - drop obsolete gconf from CONFIGURE_ARGS

Upstream changes:
 https://github.com/ibus/ibus/releases/tag/1.5.21

 1.5.21
 * Enable to run ibus-setup with a different python
 * Update ibusunicodegen.h for Unicode UCD 12.0
 * Fixes build issues
 * Enhance tests
 * Add ibus.its for IME's component files
 * Make ISO 639 language names with title
 * Keep preedit cursor_pos and visible in clearing preedit text
 * Support long sequences and multiple output characters for compose table
 * Disable panel extension for gnome-initial-setup user
 * Exit ibus-daemon with parent's death
 * Update Wayland input-method protocol to unstable v1
* Indistinguishable address of ibus-daemon (Gunnar Hjalmarsson)
* Update LOCALES_STRING (Hodong Kim)
* Fix typos (Changwoo Ryu)