Minor: fixed placeholders for compilation

Object-Oriented Programming/Type Checking/Exercise 3/task-info.yaml

@@ -3,7 +3,7 @@ files:
 - name: src/Task.kt
   visible: true
   placeholders:
-  - offset: 245
+  - offset: 115
     length: 1366
     placeholder_text: // TODO
 - name: test/Tests.kt

Usability/when Expressions/Exercise 1/task-info.yaml

@@ -3,7 +3,7 @@ files:
 - name: src/Task.kt
   visible: true
   placeholders:
-  - offset: 154
+  - offset: 155
     length: 271
     placeholder_text: TODO()
 - name: test/Tests.kt

util/test/TestAllExamples.java

@@ -3073,7 +3073,7 @@ public class TestAllExamples extends AbstractTestExamples {
 
     @Test
     public void testMain() {
-        testExample("Introduction to Objects/Packages/Exercise 3/src/Main.kt", packagesExercise3.Task3Kt::main);
+        testExample("Introduction to Objects/Packages/Exercise 3/src/Task3.kt", packagesExercise3.Task3Kt::main);
     }
 
     @Test