Normalize text for encryption

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

@@ -466,6 +466,16 @@ public class MessageHelper {
         String htmlContent = document.html();
         String plainContent = HtmlHelper.getText(htmlContent);
 
+        if (message.encrypt != null && !EntityMessage.ENCRYPT_NONE.equals(message.encrypt)) {
+            // Normalize trailing spaces and new lines
+            Log.i("Normalizing for encryption");
+            htmlContent = htmlContent.replaceAll(" +$", "")
+                    .replace("\\r?\\n", "\\r\\n");
+
+            plainContent = plainContent.replaceAll(" +$", "")
+                    .replace("\\r?\\n", "\\r\\n");
+        }
+
         BodyPart plainPart = new MimeBodyPart();
         plainPart.setContent(plainContent, "text/plain; charset=" + Charset.defaultCharset().name());