Fix various issues with forum topic importing

Fixes #201

app/tests/unit/utils/test_utils.py

@@ -16,6 +16,15 @@
 
 import user_agents
 
+from app.utils import make_valid_username
+
+
+def test_make_valid_username():
+	assert make_valid_username("rubenwardy") == "rubenwardy"
+	assert make_valid_username("Test123._-") == "Test123._-"
+	assert make_valid_username("Foo Bar") == "Foo_Bar"
+	assert make_valid_username("François") == "Fran_ois"
+
 
 def test_web_is_not_bot():
 	assert not user_agents.parse("Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:126.0) Gecko/20100101 Firefox/126.0").is_bot