Prevented challenge prize edit. Fixed edit to create modal (#9374)

website/client/components/challenges/challengeModal.vue

@@ -47,7 +47,7 @@
         label
           strong(v-once) {{$t('endDate')}}
         b-form-input.end-date-input
-      .form-group
+      .form-group(v-if='creating')
         label
           strong(v-once) {{$t('prize')}}
         input(type='number', :min='minPrize', :max='maxPrize', v-model="workingChallenge.prize")

website/client/components/challenges/myChallenges.vue

@@ -150,6 +150,7 @@ export default {
       this.filters = eventData;
     },
     createChallenge () {
+      this.$store.state.challengeOptions.workingChallenge = {};
       this.$root.$emit('show::modal', 'challenge-modal');
     },
     async loadchallanges () {