Added clear event

ref #91

src/components/donations/DonationDetail.svelte

@@ -220,7 +220,7 @@
         noOptionsMessage={$_('no-donors-found')}
         selectedValue={current_donors.find((d) => (d.id == editable.donor))}
         on:select={(selectedValue) => (editable.donor = selectedValue.detail.id)}
-        on:clear={editable.donor = null}/>
+        on:clear={()=>(editable.donor = null)}/>
     </div>
     {#if original_data.responseType == 'DISTANCEDONATION'}
       <div class=" w-full">
@@ -238,7 +238,7 @@
           noOptionsMessage={$_('no-runners-found')}
           selectedValue={undefined || current_runners.find((r) => (r.id = original_data.runner.id))}
           on:select={(selectedValue) => (editable.runner == selectedValue.detail.id)}
-          on:clear={editable.runner = null} />
+          on:clear={()=>(editable.runner = null)} />
       </div>
     {/if}
     <div class=" w-full">