Revert "chore(deps-dev): bump react-dnd-html5-backend from 2.6.0 to 16.0.1 (#788)" (#1042)

This reverts commit 2edde27.

Author: li-jia-nan

package.json

@@ -97,7 +97,7 @@
     "rc-tooltip": "^5.2.1",
     "react": "^16.0.0",
     "react-dnd": "^2.5.4",
-    "react-dnd-html5-backend": "^16.0.1",
+    "react-dnd-html5-backend": "^2.5.4",
     "react-dom": "^16.0.0",
     "react-resizable": "^1.7.5",
     "react-virtualized": "^9.12.0",