fix: revert backgroundImage schema

Author: vlatyshev

schemas/common.json

@@ -768,8 +768,16 @@
           "$ref": "common#/definitions/fitToSquare"
         },
         "backgroundImage": {
-          "type": "string",
-          "format": "uri"
+          "oneOf": [
+            {
+              "type": "string",
+              "format": "uri"
+            },
+            {
+              "type": "string",
+              "const": ""
+            }
+          ]
         },
         "type": {
           "type": "string",

test/suites/update.js

@@ -597,14 +597,6 @@ describe('update suite', function suite() {
         });
     });
 
-    it('failed to unset backgroundImage passing an empty string', async function test() {
-      meta.backgroundImage = '';
-
-      await assert.rejects(this.send({ uploadId: this.response.uploadId, username, meta }, 45000), {
-        statusCode: 400,
-      });
-    });
-
     it('remove backgroundImage', async function test() {
       await this
         .send({