fix: mispelled line in objective_description

data-raw/objective_description.txt

@@ -2,8 +2,7 @@ code	type	name	description
 l1	low	vigilance	sensibilisation for water usage reduction
 l2	low	alert	restriction of 30% of non productive water withdrawals
 l3	low	reinforced alert	restriction of 50% of water withdrawals excluding drinking water supply
-l4	low	crisis	only the drinking water supply and respect for biological life
-are insured
+l4	low	crisis	only the drinking water supply and respect for biological life are insured
 h1	high	yellow	localized overflow flooding
 h2	high	orange	flood causing major overflows
 h3	high	red	major flood, direct and widespread threat