Spell Checking does not underline misspelled words or suggest corrections.

Versions

• OS: Windows 10 20H2
• Gajim version: 1.3.2
• GTK version: 3.24.29
• Python-nbxmpp version: 2.0.2

Steps to reproduce the problem

1. Enable Menu > Gajim > Preferences > Chats "Spell Checking".
2. Open a "chat" and misspell any word into MessageInput.

Expected behavior

1. The context menu shows the "Language" menu item and all the
   dictionaries, and
2. misspelled words get underlined while "suggested corrections"
   are being listed in the context menu.

Actual behavior

1. The context menu shows the "Language" menu item and all the
   dictionaries, but
2. nothing gets underlined as misspelled or any words getting listed
   as "suggested corrections" in the context menu.

Actions taken before submitting issue

1. disabled all custom non-default plugins & custom dictionaries (Spell-Checking NOT Working)
2. installed & tried gajim portable 1.3.2 32bit/64bit (Spell-Checking NOT Working)
3. installed & tried daily snapshot gajim portable 1.3.2 32bit/64bit (Spell-Checking NOT Working)
4. installed & tried gajim portable master 32bit/64bit (Spell-Checking NOT Working)
5. installed & tried gajim 1.3.1 portable 64bit (Spell-Checking OK)