OO-4524: decrease match count by switch of checks in matrix with max 1

src/main/java/org/olat/ims/qti21/ui/components/_content/matchInteraction_kprim.html

@@ -16,14 +16,14 @@
 		<thead>
 			<tr>
 			#if($r.classContains($interaction,"choiceright"))
-				<th class="o_qti_item_kprim_text"> </th>
+				<th class="o_qti_item_kprim_text" scope="col"> </th>
 			#end
             #foreach($choice2 in $orderedSet2)
             	#set($set2Identifier = $r.toString($choice2.identifier))
-				<th class="o_qti_item_kprim_input o_qti_item_kprim_input_${set2Identifier}">$r.renderKprimSpecialFlowStatics($choice2.getFlowStatics())</th>
+				<th class="o_qti_item_kprim_input o_qti_item_kprim_input_${set2Identifier}" scope="col">$r.renderKprimSpecialFlowStatics($choice2.getFlowStatics())</th>
 			#end
 			#if(!$r.classContains($interaction,"choiceright"))
-				<th class="o_qti_item_kprim_text"> </th>
+				<th class="o_qti_item_kprim_text" scope="col"> </th>
 			#end
 			</tr>
         </thead>

src/main/webapp/static/js/jquery/qti/jquery.match.js

@@ -124,6 +124,7 @@
 								if(inputRightId === elementRightId) {
 									element.checked = false;
 									left.matchCount--;
+					                right.matchCount--;
 									settings.matchCount--;
 								}
 							}