inserted space between updates available message and link description

this changes the rendering from
  ...functionality of Jenkins.(updates available)
to 
  ...functionality of Jenkins. (updates available)
which looks nicer.

Had to use  , regular whitespace wouldn't do.

core/src/main/resources/jenkins/management/PluginsLink/info.jelly

@@ -25,6 +25,6 @@
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core">
     <j:if test="${!empty app.updateCenter.updates}">
-      <span style="color:red; font-weight:bold">(${%updates available})</span>
+      <span style="color:red; font-weight:bold">&amp;nbsp;(${%updates available})</span>
     </j:if>
 </j:jelly>
\ No newline at end of file