change et al. min (#4736)

harvard-stellenbosch-university.csl

@@ -45,7 +45,7 @@
   </macro>
   <macro name="author">
     <names variable="author">
-      <name name-as-sort-order="all" and="symbol" sort-separator=", " initialize-with="." delimiter=", " delimiter-precedes-last="never" et-al-min="9" et-al-use-first="8"/>
+      <name name-as-sort-order="all" and="symbol" sort-separator=", " initialize-with="." delimiter=", " delimiter-precedes-last="never" et-al-min="4" et-al-use-first="3"/>
       <label form="short" prefix=" " text-case="capitalize-first"/>
       <substitute>
         <names variable="editor"/>