fix: correct import statement

Author: SimonVerhoeven

src/main/kotlin/ch07/7.1.11.1_2_PlatformTypes1.kt

@@ -1,6 +1,6 @@
 package ch07.ex1_11_1_2_PlatformTypes1
 
-import ch06.Person
+import ch07.Person
 
 fun yellAtSafe(person: Person) {
  println((person.name ?: "Anyone").uppercase() + "!!!")