checkimages.py: removed unused untaggedGenerator

untaggedGenerator in checkimages uses an obsolete toolserver tool.

Bug: 72496

Change-Id: I634f001c9016239b2e6cc646bbc4272806a79c02
[FIX] pagegen tests: normalize page titles

On the wiktionary the main namespace is case sensitive but the test
didn't account for this.

Change-Id: I1e6f64eee2fe81754011c7fa13db8405de14626e
Merge "checkimages.py: removed unused untaggedGenerator"