admin: have a specific error message when trying to add a pending creation on a deleted user

backend/src/graphql/resolver/AdminResolver.ts

@@ -83,10 +83,13 @@ export class AdminResolver {
   async createPendingCreation(
     @Args() { email, amount, memo, creationDate, moderator }: CreatePendingCreationArgs,
   ): Promise<number[]> {
-    const user = await User.findOne({ email })
+    const user = await User.findOne({ email }, { withDeleted: true })
     if (!user) {
       throw new Error(`Could not find user with email: ${email}`)
     }
+    if (user.deletedAt) {
+      throw new Error('This user was deleted. Cannot make a creation.')
+    }
     if (!user.emailChecked) {
       throw new Error('Creation could not be saved, Email is not activated')
     }