Update EventHub.json (#17565)

Author: JoshLove-msft

specification/eventgrid/data-plane/Microsoft.EventHub/stable/2018-01-01/EventHub.json

@@ -11,9 +11,10 @@
       "description": "Schema of the Data property of an EventGridEvent for a Microsoft.EventHub.CaptureFileCreated event.",
       "type": "object",
       "properties": {
-        "fileurl": {
+        "fileUrl": {
           "description": "The path to the capture file.",
-          "type": "string"
+          "type": "string",
+          "x-ms-client-name": "fileurl"
         },
         "fileType": {
           "description": "The file type of the capture file.",