DeleteSideEffectsAwareFix: do not remove message for non-expression-statement

The fix is still useful if invoked for if condition/switch expression/etc. Fixes IDEA-180372.

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/emptyStatement/afterExtractFullCondition.java

@@ -0,0 +1,11 @@
+// "Extract side effect" "true"
+class Test {
+  void test(int x) {
+      foo(x, 2);
+  }
+
+  boolean foo(int x, int y) {
+    System.out.println(x);
+    return x > y;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/emptyStatement/beforeExtractFullCondition.java

@@ -0,0 +1,13 @@
+// "Extract side effect" "true"
+class Test {
+  void test(int x) {
+    i<caret>f(foo(x, 2)) {
+
+    }
+  }
+
+  boolean foo(int x, int y) {
+    System.out.println(x);
+    return x > y;
+  }
+}