update empty string to null

src/pages/ProjectEditPage.vue

@@ -10,13 +10,12 @@
 
 <script setup lang="ts">
   import { ref, computed, watch } from 'vue'
-  import { useRouter, useRoute } from 'vue-router'
+  import { useRouter } from 'vue-router'
   import projectBlock from 'components/projectBlock.vue'
   import { useProjectsStore } from 'stores/projects'
   import type { ProjectParams } from 'types/Project'
 
   const router = useRouter()
-  const route = useRoute()
   const projectsStore = useProjectsStore()
 
   const projectId = computed(() => projectsStore.currentProjectId)