www-react: Fix crash on build ending #2

Job	Run time
DB / MySQL 5	8m 21s
DB / MySQL latest	12m 21s
Win / python 3.8	9m 16s
Win / python 3.9	8m 50s
DB / PostgreSQL 9 / psycopg2	10m 1s
Win / python 3.10	8m 8s
DB / PostgreSQL 9 / pg8000	10m 0s
Win / python 3.11	10m 15s
DB / PostgreSQL latest / psycopg2	8m 31s
DB / PostgreSQL latest / pg8000	10m 26s
	1h 36m 9s

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