typo fix in hint message if2

Author: bufo24

info.toml

@@ -158,7 +158,7 @@ path = "exercises/if/if2.rs"
 mode = "test"
 hint = """
 For that first compiler error, it's important in Rust that each conditional
-block return the same type! To get the tests passing, you will need a couple
+block returns the same type! To get the tests passing, you will need a couple
 conditions checking different input values."""
 
 # TEST 1