dxDiagram - fix exception on dragging diagram inside dxTabs (T1266168) (#28676)

Author: romanresh

packages/devextreme/package.json

@@ -30,7 +30,7 @@
   "dependencies": {
     "@babel/runtime": "^7.12.1",
     "@devextreme/runtime": "3.0.13",
-    "devexpress-diagram": "2.2.14",
+    "devexpress-diagram": "2.2.15",
     "devexpress-gantt": "4.1.56",
     "devextreme-quill": "1.7.1",
     "inferno": "^7.4.9",