Update frontiers.csl (#6014)

frontiers.csl

@@ -12,10 +12,13 @@
       <name>Julian Onions</name>
       <email>julian.onions@gmail.com</email>
     </contributor>
+    <contributor>
+      <name>Patrick O'Brien</name>
+    </contributor>
     <category citation-format="author-date"/>
     <category field="generic-base"/>
     <summary>Style for the Open Access Frontiers in ... Journals</summary>
-    <updated>2012-09-27T22:06:38+00:00</updated>
+    <updated>2022-04-12T22:06:38+00:00</updated>
     <rights license="http://creativecommons.org/licenses/by-sa/3.0/">This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License</rights>
   </info>
   <macro name="editor">
@@ -47,7 +50,7 @@
   <macro name="access">
     <choose>
       <if variable="DOI">
-        <text variable="DOI" prefix="doi:"/>
+        <text variable="DOI" prefix="doi: "/>
       </if>
       <else-if variable="URL">
         <text value="Available at:" suffix=" "/>