Prevent multiple column separators

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

@@ -919,8 +919,7 @@ public class HtmlHelper {
                             col.removeAttr("x-line-before");
                     }
 
-                    if (next != null && col.childNodeSize() > 0)
+                    col.attr("x-column", "true");
-                        col.appendText("\u2002"); // ensp
                 }
 
                 if (merge.size() != 0)
@@ -2383,6 +2382,12 @@ public class HtmlHelper {
                             ssb.length() > 0 && ssb.charAt(ssb.length() - 1) == '\n')
                         ssb.append('\n');
 
+                    if ("true".equals(element.attr("x-column")) &&
+                            ssb.length() > 1 &&
+                            ssb.charAt(ssb.length() - 1) != '\n' &&
+                            ssb.charAt(ssb.length() - 1) != '\u2002')
+                        ssb.append('\u2002'); // ensp
+
                     if (debug)
                         ssb.append("[/" + element.tagName() + "]");
                 }