Confirm showing images in composer

app/src/main/java/eu/faircode/email/FragmentCompose.java

@@ -915,8 +915,17 @@ public class FragmentCompose extends FragmentBase {
         ibReferenceImages.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                ibReferenceImages.setVisibility(View.GONE);
-                onReferenceImages();
+                new AlertDialog.Builder(v.getContext())
+                        .setMessage(R.string.title_ask_show_image)
+                        .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                            @Override
+                            public void onClick(DialogInterface dialog, int which) {
+                                ibReferenceImages.setVisibility(View.GONE);
+                                onReferenceImages();
+                            }
+                        })
+                        .setNegativeButton(android.R.string.cancel, null)
+                        .show();
             }
         });