Move self._gsettings.connect('changed', self.on_gsettings_value_chang…

…ed) in __init__() *after* defining self._set_get_functions

Resolves: #454
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2171140

I still cannot reproduce this myself because it seems highly timing
dependent, but I believe I have finally understood the problem, I
believe this commit should fix it.

engine/hunspell_table.py

@@ -159,7 +159,6 @@ def __init__(
         self._setup_pid = 0
         self._gsettings = Gio.Settings(
             schema='org.freedesktop.ibus.engine.typing-booster')
-        self._gsettings.connect('changed', self.on_gsettings_value_changed)
 
         self._prop_dict: Dict[str, IBus.Property] = {}
         self._sub_props_dict: Dict[str, IBus.PropList] = {}
@@ -778,6 +777,7 @@ def __init__(
                 'set': self.set_google_application_credentials,
                 'get': self.get_google_application_credentials},
         }
+        self._gsettings.connect('changed', self.on_gsettings_value_changed)
 
         self._clear_input_and_update_ui()