Fix removing html tags for inline preview

Pages/BlogPost.cshtml

@@ -17,7 +17,7 @@
 
 	var desc = Model.Post.Content;
 	desc = Regex.Replace(desc, @"\s+", " "); // collapse whitespace
-	desc = Regex.Replace(desc, @"(?i)<\/?[aibu][^>]*>", ""); // remove <a>, <i>, <b> and <u> html tags
+	desc = Regex.Replace(desc, @"(?i)<\/?(?:[aibu]|em)[^>]*>", ""); // remove <a>, <i>, <b>, <u> and <em> html tags
 	desc = desc.Trim(); // remove leading and trailing whitespace
 	desc = Regex.Match(desc, @"<p>([^<].*?)<\/p>").Groups[1].ToString().GetUntil("."); // get first sentence
 	ViewData["og-desc"] = desc;