Add when branches: remove unnecessary blank line

#KT-30426 Fixed

idea/testData/quickfix/when/addRemainingBranchesBlankLineWithComment.kt.after

@@ -0,0 +1,13 @@
+// "Add remaining branches" "true"
+// WITH_RUNTIME
+
+sealed class A
+class B : A()
+
+fun test(a: A) {
+    val r = when (a) {
+
+        // comment
+        is B -> TODO()
+    }
+}