URL routing will skip if the first character is a number

[sdhczw]

Describe the bug

1. The api code is

   @handler Upload3DHandler
   post /3d(Void) returns (FileUploadResp);

2. generated code

   		{
    			Method:  http.MethodPost,
    			Path:    "/d",
    			Handler: upload.Upload3DHandler(serverCtx),
    		},

Environments (please complete the following information):

• OS: [e.g. Linux]
• go-zero version [e.g. 1.3.4]
• goctl version [e.g. 1.3.8, optional]

More description
Add any other context about the problem here.