Update JSON example

Author: Clare Zheng (Shanghai Wicresoft Co Ltd)

articles/data-factory/connector-google-bigquery-legacy.md

@@ -154,7 +154,7 @@ Set "authenticationType" property to **ServiceAuthentication**, and specify the
             "requestGoogleDriveScope" : true,
             "authenticationType" : "ServiceAuthentication",
             "email": "<email>",
-            "keyFilePath": "<.p12 or .json key path on the IR machine>"
+            "keyFilePath": "<.json key path on the IR machine>"
         },
         "connectVia": {
             "referenceName": "<name of Self-hosted Integration Runtime>",