clamp the biogen amount to within the limits allowed by the UI (#43792)

code/modules/hydroponics/biogenerator.dm

@@ -309,6 +309,8 @@
 
 	else if(href_list["create"])
 		var/amount = (text2num(href_list["amount"]))
+		//Can't be outside these (if you change this keep a sane limit)
+		amount = CLAMP(amount, 1, 10)
 		var/datum/design/D = locate(href_list["create"])
 		create_product(D, amount)
 		updateUsrDialog()