Specify email image width both in attributes and style

Apparently Apple mail ignores the width/height if specified in
attributes, but work in style, so let's do both.

Ref: https://www.caniemail.com/features/html-width/, point 3.

Author: tbussmann

templates/news/mail/pgproject.html

@@ -4,8 +4,8 @@
 
 {%block content%}
 <div>
-  <img style="float: left" height="50" width="50" src="cid:slonik.png" alt="PostgreSQL logo">
-  <img style="float: right" height="50" width="50" src="cid:slonik.png" alt="PostgreSQL logo">
+  <img style="float: left; width: 50px" height="50" width="50" src="cid:slonik.png" alt="PostgreSQL logo">
+  <img style="float: right; width: 50px" height="50" width="50" src="cid:slonik.png" alt="PostgreSQL logo">
   <h1>{{news.title}}</h1>
 </div>
 {{news.content|markdown}}