Java to Kotlin converter: fixed exception on conversion

j2k/tests/testData/ast/foreachStatement/nullableIterable.kt

@@ -0,0 +1,9 @@
+class A {
+    var list: List<String>? = null
+
+    fun foo() {
+        for (e in list!!) {
+            System.out.println(e)
+        }
+    }
+}