Fix minimap removeimage proc not checking z level correctly #13756

Job	Run time
Compile Maps	1m 16s
Run Linters	1m 57s
Find Maps to Test	12s
Windows Build	2m 20s
Unit Tests (corsat) / run_unit_tests	6m 41s
Unit Tests (bigredv2) / run_unit_tests	5m 46s
Unit Tests (almayer) / run_unit_tests	5m 48s
Unit Tests (chinook) / run_unit_tests	5m 50s
Unit Tests (desert_dam) / run_unit_tests	6m 0s
Unit Tests (fiorina_sciannex) / run_unit_tests	5m 44s
Unit Tests (ice_colony_v2) / run_unit_tests	6m 8s
Unit Tests (lv522_chances_claim) / run_unit_tests	5m 48s
Unit Tests (kutjevo) / run_unit_tests	6m 11s
Unit Tests (lv624) / run_unit_tests	5m 55s
Unit Tests (new_varadero) / run_unit_tests	5m 57s
Unit Tests (override_ground) / run_unit_tests	6m 5s
Unit Tests (override_ship) / run_unit_tests	5m 53s
Unit Tests (runtime) / run_unit_tests	6m 3s
Unit Tests (prison_station_fop) / run_unit_tests	6m 3s
Unit Tests (shivas_snowball) / run_unit_tests	5m 41s
Unit Tests (sorokyne_strata) / run_unit_tests	6m 24s
Unit Tests (whiskey_outpost_v2) / run_unit_tests	6m 40s
Alternate Tests (515, 1603, lv624) / run_unit_tests	5m 46s
Check Alternate Tests	1s
	2h 0m 9s

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