docs: dedup repeated sentence

Author: alexfertel

exercises/quiz1.rs

@@ -9,7 +9,7 @@
 // - An apple costs 2 rustbucks.
 // - If Mary buys more than 40 apples, each apple only costs 1 rustbuck!
 // Write a function that calculates the price of an order of apples given the
-// quantity bought. No hints this time!
+// quantity bought.
 //
 // No hints this time ;)