MDL-58586 css: add margin to userpictures

Boost has a right margin on the userpicture but this is missing in bootstrapbase (it is
added only on random pages).

Add a margin to bootstrapbase so it matches boost.

theme/bootstrapbase/less/moodle/core.less

@@ -222,6 +222,9 @@ a.autolink.glossary:hover {
 .pagingbar .thispage {
     font-weight: bold;
 }
+img.userpicture {
+    margin-right: 5px;
+}
 img.resize {
     height: 1em;
     width: 1em;
@@ -559,7 +562,6 @@ a.skip:active {
 }
 .notepost .userpicture {
     float: left;
-    margin-right: 5px;
 }
 .notepost .content,
 .notepost .footer {

theme/bootstrapbase/style/moodle.css

@@ -2530,6 +2530,9 @@ a.autolink.glossary:hover {
 .pagingbar .thispage {
   font-weight: bold;
 }
+img.userpicture {
+  margin-right: 5px;
+}
 img.resize {
   height: 1em;
   width: 1em;
@@ -2856,7 +2859,6 @@ a.skip:active {
 }
 .notepost .userpicture {
   float: left;
-  margin-right: 5px;
 }
 .notepost .content,
 .notepost .footer {