CodeGen from PR 15609 in Azure/azure-rest-api-specs

updated login help text (#15609)

Author: SDKAuto

schemas/2017-12-01/Microsoft.DBforMySQL.json

@@ -693,7 +693,7 @@
       "properties": {
         "administratorLogin": {
           "type": "string",
-          "description": "The administrator's login name of a server. Can only be specified when the server is being created (and is required for creation)."
+          "description": "The administrator's login name of a server. Can only be specified when the server is being created (and is required for creation). The login name is required when updating password."
         },
         "administratorLoginPassword": {
           "type": "string",