Fixed error versions for hyperf/engine. (#7429)

Author: limingxinleo

composer.json

@@ -22,7 +22,7 @@
         "hyperf/context": "~3.1.0",
         "hyperf/contract": "~3.1.0",
         "hyperf/coroutine": "~3.1.0",
-        "hyperf/engine": "~3.1.0",
+        "hyperf/engine": "^2.0",
         "hyperf/event": "~3.1.0",
         "hyperf/grpc": "~3.1.0",
         "jean85/pretty-package-versions": "^1.2 || ^2.0"