change et-al settings (#5628)

via https://forums.zotero.org/discussion/comment/390091/#Comment_390091

Author: POBrien333

netherlands-journal-of-geosciences-geologie-en-mijnbouw.csl

@@ -1422,7 +1422,7 @@
       </else-if>
     </choose>
   </macro>
-  <citation et-al-min="6" et-al-use-first="1" et-al-subsequent-min="3" et-al-subsequent-use-first="1" disambiguate-add-year-suffix="true" disambiguate-add-names="true" disambiguate-add-givenname="true" collapse="year" givenname-disambiguation-rule="primary-name">
+  <citation et-al-min="3" et-al-use-first="1" disambiguate-add-year-suffix="true" disambiguate-add-names="true" disambiguate-add-givenname="true" collapse="year" givenname-disambiguation-rule="primary-name">
     <sort>
       <key macro="author" names-min="8" names-use-first="6"/>
       <key macro="issued-sort"/>